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This means it might contain formatting issues, incorrect code, conceptual problems, or other severe issues.
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{{task|Arithmetic operations}} [[Category:Simple]]
;Task: Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
8th
[ 1.0, 2.3, 1.1, 5.0, 3, 2.8, 2.01, 3.14159 ] ' n:max 0 a:reduce . cr
Output: 5
ACL2
(defun maximum (xs) (if (endp (rest xs)) (first xs) (max (first xs) (maximum (rest xs)))))
ActionScript
function max(... args):Number { var curMax:Number = -Infinity; for(var i:uint = 0; i < args.length; i++) curMax = Math.max(curMax, args[i]); return curMax; }
Ada
The keys for this task are initializing the compared value to the 'First value of the element type, and use of an unconstrained array type.
with Ada.Text_Io;
procedure Max_Test isco
-- substitute any array type with a scalar element
type Flt_Array is array (Natural range <>) of Float;
-- Create an exception for the case of an empty array
Empty_Array : Exception;
function Max(Item : Flt_Array) return Float is
Max_Element : Float := Float'First;
begin
if Item'Length = 0 then
raise Empty_Array;
end if;
for I in Item'range loop
if Item(I) > Max_Element then
Max_Element := Item(I);
end if;
end loop;
return Max_Element;
end Max;
Buf : Flt_Array := (-275.0, -111.19, 0.0, -1234568.0, 3.14159, -3.14159);
begin
Ada.Text_IO.Put_Line(Float'Image(Max(Buf)));
end Max_Test;
A generic function Max to deal with any floating-point type.
generic
type Item is digits <>;
type Items_Array is array (Positive range <>) of Item;
function Generic_Max (List : Items_Array) return Item;
Implementation of:
function Generic_Max (List : Items_Array) return Item is
Result : Item := List (List'First);
begin
for Index in List'First + 1..List'Last loop
Result := Item'Max (Result, List (Index));
end loop;
return Result;
end Generic_Max;
When the argument array is empty, Constraint_Error exception is propagated, because array indexing is checked in Ada. Note also use of the floating-type attribute Max.
Aime
integer
lmax(list l)
{
integer max, x;
max = l[0];
for (, x in l) {
if (max < x) {
max = x;
}
}
max;
}
or
integer
lmax(list l)
{
integer max;
max = l[0];
l.ucall(max_i, 1, max);
max;
}
ALGOL 68
{{works with|ALGOL 68|Revision 1 - no extensions to language used}}
{{works with|ALGOL 68G|Any - tested with release [http://sourceforge.net/projects/algol68/files/algol68g/algol68g-1.18.0/algol68g-1.18.0-9h.tiny.el5.centos.fc11.i386.rpm/download 1.18.0-9h.tiny]}} {{wont work with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release [http://sourceforge.net/projects/algol68/files/algol68toc/algol68toc-1.8.8d/algol68toc-1.8-8d.fc9.i386.rpm/download 1.8-8d] - due to extensive use of FORMATted transput}}
# substitute any array type with a scalar element #
MODE FLT = REAL;
# create an exception for the case of an empty array #
PROC raise empty array = VOID:(
GO TO except empty array
);
PROC max = ([]FLT item)FLT:
BEGIN
IF LWB item > UPB item THEN
raise empty array; SKIP
ELSE
FLT max element := item[LWB item];
FOR i FROM LWB item + 1 TO UPB item DO
IF item[i] > max element THEN
max element := item[i]
FI
OD;
max element
FI
END # max #;
test:(
[]FLT buf = (-275.0, -111.19, 0.0, -1234568.0, pi, -pi);
print((max(buf),new line)) EXIT
except empty array:
SKIP
)
{{out}}
+3.14159265358979e +0
ALGOL W
begin
% simple list type %
record IntList( integer val; reference(IntList) next );
% find the maximum element of an IntList, returns 0 for an empty list %
integer procedure maxElement( reference(IntList) value list ) ;
begin
integer maxValue;
reference(IntList) listPos;
maxValue := 0;
listPos := list;
if listPos not = null then begin
% non-empty list %
maxValue := val(listPos);
listPos := next(listPos);
while listPos not = null do begin
if val(listPos) > maxValue then maxValue := val(listPos);
listPos := next(listPos)
end while_listPos_ne_null ;
end if_listPos_ne_null ;
maxValue
end maxElement ;
% test the maxElement procedure %
write( maxElement( IntList( -767, IntList( 2397, IntList( 204, null ) ) ) ) )
end.
{{out}}
2397
AntLang
max|range[10]
APL
LIST←2 4 6 3 8
⌈/LIST
{{out}}
8
AppleScript
max({1, 2, 3, 4, 20, 6, 11, 3, 9, 7}) on max(aList) set _curMax to first item of aList repeat with i in (rest of aList) if i > _curMax then set _curMax to contents of i end repeat return _curMax end max
To find the greatest elements of lists which may contain data types other than numbers, we can write a more generic '''maximumBy''' function, which returns the maximum value from an array containing a series of any consistent data type, and which takes a type-specific comparison function as an argument.
{{trans|JavaScript}}
-- maximumByMay :: (a -> a -> Ordering) -> [a] -> Maybe a on maximumByMay(f, xs) set cmp to mReturn(f) script max on |λ|(a, b) if cmp's |λ|(a, b) < 0 then b else a end if end |λ| end script foldl1May(max, xs) end maximumByMay -- TEST ----------------------------------------------------------------------- on run set lstWords to ["alpha", "beta", "gamma", "delta", "epsilon", ¬ "zeta", "eta", "theta", "iota", "kappa", "|λ|", "mu"] set lstCities to [{name:"Shanghai", population:24.15}, ¬ {name:"Karachi", population:23.5}, ¬ {name:"Beijing", population:21.5}, ¬ {name:"Tianjin", population:14.7}, ¬ {name:"Istanbul", population:14.4}, ¬ {name:"Lagos", population:13.4}, ¬ {name:"Tokyo", population:13.3}] script population on |λ|(x) population of x end |λ| end script return catMaybes({¬ maximumByMay(comparing(|length|), lstWords), ¬ maximumByMay(comparing(|length|), {}), ¬ maximumByMay(comparing(population), lstCities)}) --> {"epsilon", {name:"Shanghai", population:24.15}} end run -- GENERIC FUNCTIONS ---------------------------------------------------------- -- catMaybes :: [Maybe a] -> [a] on catMaybes(mbs) script emptyOrListed on |λ|(m) if nothing of m then {} else {just of m} end if end |λ| end script concatMap(emptyOrListed, mbs) end catMaybes -- comparing :: (a -> b) -> (a -> a -> Ordering) on comparing(f) set mf to mReturn(f) script on |λ|(a, b) set x to mf's |λ|(a) set y to mf's |λ|(b) if x < y then -1 else if x > y then 1 else 0 end if end if end |λ| end script end comparing -- concatMap :: (a -> [b]) -> [a] -> [b] on concatMap(f, xs) set acc to {} tell mReturn(f) repeat with x in xs set acc to acc & |λ|(contents of x) end repeat end tell return acc end concatMap -- foldl1May :: (a -> a -> a) -> [a] -> Maybe a on foldl1May(f, xs) set lng to length of xs if lng > 0 then if lng > 1 then tell mReturn(f) set v to item 1 of xs set lng to length of xs repeat with i from 2 to lng set v to |λ|(v, item i of xs, i, xs) end repeat return just(v) end tell else just(item 1 of xs) end if else nothing("Empty list") end if end foldl1May -- just :: a -> Just a on just(x) {nothing:false, just:x} end just -- length :: [a] -> Int on |length|(xs) length of xs end |length| -- max :: Ord a => a -> a -> a on max(x, y) if x > y then x else y end if end max -- nothing :: () -> Nothing on nothing(msg) {nothing:true, msg:msg} end nothing -- Lift 2nd class handler function into 1st class script wrapper -- mReturn :: Handler -> Script on mReturn(f) if class of f is script then f else script property |λ| : f end script end if end mReturn
{{Out}}
{"epsilon", {name:"Shanghai", population:24.15}}
Applesoft BASIC
100 REMMAX
110 R$ = "":E$ = ""
120 L = LEN (L$)
130 IF L = 0 THEN RETURN
140 FOR I = 1 TO L
150 C$ = MID$ (L$,I,1)
160 SP = C$ = " "
170 IF SP THEN GOSUB 200
180 E$ = E$ + C$
190 NEXT I
200 C$ = ""
210 IF E$ = "" THEN RETURN
220 V = VAL (E$):V$ = R$
230 E$ = "":E = V$ = ""
240 IF E AND V = 0 THEN RETURN
250 R$ = STR$ (V)
260 IF E THEN RETURN
270 R = VAL (V$)
280 IF R < V THEN RETURN
290 R$ = V$: RETURN
L$ = "1 2 3 4 20 6 11 3 9 7"
GOSUB 100MAX
PRINT R$
{{Out}}
20
ARM Assembly
{{works with|as|Raspberry Pi}}
/* ARM assembly Raspberry PI */
/* program rechMax.s */
/* Constantes */
.equ STDOUT, 1 @ Linux output console
.equ EXIT, 1 @ Linux syscall
.equ WRITE, 4 @ Linux syscall
/*********************************/
/* Initialized data */
/*********************************/
.data
szMessResult: .ascii "Max number is = " @ message result
sMessValeur: .fill 12, 1, ' '
.ascii " rank = "
sMessRank: .fill 12, 1, ' '
.ascii " address (hexa) = "
sMessAddress: .fill 12, 1, ' '
.asciz "\n"
tTableNumbers: .int 50
.int 12
.int -1000
.int 40
.int 255
.int 60
.int 254
.equ NBRANKTABLE, (. - tTableNumbers) / 4 @ number table posts
/*********************************/
/* UnInitialized data */
/*********************************/
.bss
/*********************************/
/* code section */
/*********************************/
.text
.global main
main: @ entry of program
push {fp,lr} @ saves 2 registers
ldr r1,iAdrtTableNumbers
mov r2,#0
ldr r4,[r1,r2,lsl #2]
mov r3,r2
add r2,#1
1:
cmp r2,#NBRANKTABLE
bge 2f
ldr r0,[r1,r2,lsl #2]
cmp r0,r4
movgt r4,r0
movgt r3,r2
add r2,#1
b 1b
2:
mov r0,r4
ldr r1,iAdrsMessValeur
bl conversion10S @ call conversion
mov r0,r3
ldr r1,iAdrsMessRank
bl conversion10 @ call conversion
ldr r0,iAdrtTableNumbers
add r0,r3,lsl #2
ldr r1,iAdrsMessAddress
bl conversion16 @ call conversion
ldr r0,iAdrszMessResult
bl affichageMess @ display message
100: @ standard end of the program
mov r0, #0 @ return code
pop {fp,lr} @restaur 2 registers
mov r7, #EXIT @ request to exit program
swi 0 @ perform the system call
iAdrtTableNumbers: .int tTableNumbers
iAdrsMessValeur: .int sMessValeur
iAdrsMessRank: .int sMessRank
iAdrsMessAddress: .int sMessAddress
iAdrszMessResult: .int szMessResult
/******************************************************************/
/* display text with size calculation */
/******************************************************************/
/* r0 contains the address of the message */
affichageMess:
push {fp,lr} /* save registres */
push {r0,r1,r2,r7} /* save others registers */
mov r2,#0 /* counter length */
1: /* loop length calculation */
ldrb r1,[r0,r2] /* read octet start position + index */
cmp r1,#0 /* if 0 its over */
addne r2,r2,#1 /* else add 1 in the length */
bne 1b /* and loop */
/* so here r2 contains the length of the message */
mov r1,r0 /* address message in r1 */
mov r0,#STDOUT /* code to write to the standard output Linux */
mov r7, #WRITE /* code call system "write" */
swi #0 /* call systeme */
pop {r0,r1,r2,r7} /* restaur others registers */
pop {fp,lr} /* restaur des 2 registres */
bx lr /* return */
/******************************************************************/
/* Converting a register to hexadecimal */
/******************************************************************/
/* r0 contains value and r1 address area */
conversion16:
push {r1-r4,lr} /* save registers */
mov r2,#28 @ start bit position
mov r4,#0xF0000000 @ mask
mov r3,r0 @ save entry value
1: @ start loop
and r0,r3,r4 @value register and mask
lsr r0,r2 @ move right
cmp r0,#10 @ compare value
addlt r0,#48 @ <10 ->digit
addge r0,#55 @ >10 ->letter A-F
strb r0,[r1],#1 @ store digit on area and + 1 in area address
lsr r4,#4 @ shift mask 4 positions
subs r2,#4 @ counter bits - 4 <= zero ?
bge 1b @ no -> loop
@end
pop {r1-r4,lr} @ restaur registres
bx lr @return
/******************************************************************/
/* Converting a register to a decimal */
/******************************************************************/
/* r0 contains value and r1 address area */
conversion10:
push {r1-r4,lr} /* save registers */
mov r3,r1
mov r2,#10
1: @ start loop
bl divisionpar10 @ r0 <- dividende. quotient ->r0 reste -> r1
add r1,#48 @ digit
strb r1,[r3,r2] @ store digit on area
sub r2,#1 @ previous position
cmp r0,#0 @ stop if quotient = 0 */
bne 1b @ else loop
@ and move spaves in first on area
mov r1,#' ' @ space
2:
strb r1,[r3,r2] @ store space in area
subs r2,#1 @ @ previous position
bge 2b @ loop if r2 >= zéro
100:
pop {r1-r4,lr} @ restaur registres
bx lr @return
/***************************************************/
/* Converting a register to a signed decimal */
/***************************************************/
/* r0 contains value and r1 area address */
conversion10S:
push {r0-r4,lr} @ save registers
mov r2,r1 /* debut zone stockage */
mov r3,#'+' /* par defaut le signe est + */
cmp r0,#0 @ negative number ?
movlt r3,#'-' @ yes
mvnlt r0,r0 @ number inversion
addlt r0,#1
mov r4,#10 @ length area
1: @ start loop
bl divisionpar10
add r1,#48 @ digit
strb r1,[r2,r4] @ store digit on area
sub r4,r4,#1 @ previous position
cmp r0,#0 @ stop if quotient = 0
bne 1b
strb r3,[r2,r4] @ store signe
subs r4,r4,#1 @ previous position
blt 100f @ if r4 < 0 -> end
mov r1,#' ' @ space
2:
strb r1,[r2,r4] @store byte space
subs r4,r4,#1 @ previous position
bge 2b @ loop if r4 > 0
100:
pop {r0-r4,lr} @ restaur registers
bx lr
/***************************************************/
/* division par 10 signé */
/* Thanks to http://thinkingeek.com/arm-assembler-raspberry-pi/*
/* and http://www.hackersdelight.org/ */
/***************************************************/
/* r0 dividende */
/* r0 quotient */
/* r1 remainder */
divisionpar10:
/* r0 contains the argument to be divided by 10 */
push {r2-r4} /* save registers */
mov r4,r0
ldr r3, .Ls_magic_number_10 /* r1 <- magic_number */
smull r1, r2, r3, r0 /* r1 <- Lower32Bits(r1*r0). r2 <- Upper32Bits(r1*r0) */
mov r2, r2, ASR #2 /* r2 <- r2 >> 2 */
mov r1, r0, LSR #31 /* r1 <- r0 >> 31 */
add r0, r2, r1 /* r0 <- r2 + r1 */
add r2,r0,r0, lsl #2 /* r2 <- r0 * 5 */
sub r1,r4,r2, lsl #1 /* r1 <- r4 - (r2 * 2) = r4 - (r0 * 10) */
pop {r2-r4}
bx lr /* leave function */
.align 4
.Ls_magic_number_10: .word 0x66666667
Arturo
arr #(5 4 2 9 7 3)
print $(max arr)
{{out}}
9
AutoHotkey
CSV Data
list = 1,5,17,-2
Loop Parse, list, `,
x := x < A_LoopField ? A_LoopField : x
MsgBox Max = %x%
=== Pseudo-arrays ===
list = 1,5,17,-2
StringSplit, list, list,`, ; creates a pseudo-array
Loop % List0
x := x < List%A_Index% ? List%A_Index% : x
MsgBox Max = %x%
True arrays
{{works with|AutoHotkey_L}}
List := [1,5,17,-2]
For each, value in List
x := x < value ? value : x
MsgBox Max = %x%
AWK
One-liner:
$ awk 'func max(a){for(i in a)if(a[i]>r)r=a[i];return r}BEGIN{a[0]=42;a[1]=33;a[2]=21;print max(a)}'
42
More readable version:
# Usage: awk -f greatest_list_element.awk
#
function max(a) {
for(i in a) if(a[i]>r) r=a[i];
return r
}
#
BEGIN { a[0]=42;
a[1]=33;
a[2]=21;
print max(a)
}
Axe
This example assumes the array is null-terminated so that the program can stop at the end of the data.
Lbl MAX
0→M
While {r₁}
{r₁}>M?{r₁}→M
End
M
Return
BASIC
{{works with|QBasic}}
DECLARE SUB addVal (value AS INTEGER)
DECLARE FUNCTION findMax% ()
REDIM SHARED vals(0) AS INTEGER
DIM SHARED valCount AS INTEGER
DIM x AS INTEGER, y AS INTEGER
valCount = -1
'''''begin test run
RANDOMIZE TIMER
FOR x = 1 TO 10
y = INT(RND * 100)
addVal y
PRINT y; " ";
NEXT
PRINT ": "; findMax
'''''end test run
SUB addVal (value AS INTEGER)
DIM tmp AS INTEGER
IF valCount > -1 THEN
'this is needed for BASICs that don't support REDIM PRESERVE
REDIM v2(valCount) AS INTEGER
FOR tmp = 0 TO valCount
v2(tmp) = vals(tmp)
NEXT
END IF
valCount = valCount + 1
REDIM vals(valCount)
IF valCount > 0 THEN
'also needed for BASICs that don't support REDIM PRESERVE
FOR tmp = 0 TO valCount - 1
vals(tmp) = v2(tmp)
NEXT
END IF
vals(valCount) = value
END SUB
FUNCTION findMax%
DIM tmp1 AS INTEGER, tmp2 AS INTEGER
FOR tmp1 = 0 TO valCount
IF vals(tmp1) > tmp2 THEN tmp2 = vals(tmp1)
NEXT
findMax = tmp2
END FUNCTION
{{Out}}
8162 5139 7004 7393 5151 4476 577 4419 3333 4649 : 8162
=
BaCon
=
' Greatest element from list
' Populate sample array of numbers
READ elements
DECLARE numbers TYPE NUMBER ARRAY elements
FOR i = 0 TO elements - 1
READ numbers[i]
NEXT
DATA 6
DATA 100,-2,300,4,500,6
' Demonstrate the function
PRINT greatest(elements, numbers)
END
' Return greatest element given count and list of numbers
FUNCTION greatest(n, NUMBER a[])
LOCAL mx = a[0]
FOR i = 1 TO n - 1
mx = MAX(mx, a[i])
NEXT
RETURN mx
END FUNCTION
{{out}}
prompt$ ./greatest-element
500
'''See also:''' [[#BBC BASIC|BBC BASIC]], [[#Liberty BASIC|Liberty BASIC]], [[#PowerBASIC|PowerBASIC]], [[#PureBasic|PureBasic]], [[#Run BASIC|Run BASIC]], [[#TI-89 BASIC|TI-89 BASIC]], [[#Visual Basic|Visual Basic]]
Batch File
::max.cmd
@echo off
setlocal enabledelayedexpansion
set a=.%~1
if "%a%" equ "." set /p a="Input stream: "
call :max res %a%
echo %res%
endlocal
goto :eof
:max
set %1=%2
:loop
shift /2
if "%2" equ "" goto :eof
if %2 gtr !%1! set res=%2
goto loop
''Invocation from command line or from internal prompt''
max "123 456 3 234243 12"
234243
>max
Input stream: 5 4 3 2 67 1
67
BBC BASIC
ListOfValues$ = "13, 0, -6, 2, 37, -10, 12"
PRINT "Maximum value = " ; FNmax(ListOfValues$)
END
DEF FNmax(list$)
LOCAL index%, number, max
max = VAL(list$)
REPEAT
index% = INSTR(list$, ",", index%+1)
number = VAL(MID$(list$, index%+1))
IF number > max THEN max = number
UNTIL index% = 0
= max
bc
define m(a[], n) {
auto m, i
m = a[0]
for (i = 1; i < n; i++) {
if (a[i] > m) m = a[i]
}
return(m)
}
Befunge
001pv <
>&:01g`#v_1+#^_01g.@
^p10 <
Only works with positive integers. List must be terminated with -1.
Bracmat
When comparing two rational numbers, Bracmat compares numerically. In all other cases Bracmat compares lexically.
{{Out}}
```txt
1: mies
2:
3: 3365864921428443
Brat
Arrays have a max function, but here's a manual implementation.
max = { list |
list.reduce { n, max |
true? n > max
{ max = n }
{ max }
}
}
p max [3 4 1 2]
Burlesque
blsq ) {88 99 77 66 55}>]
99
C
This works well with floats. Replace with double, int or what-have-you before passing a different data type.
#include <assert.h> float max(unsigned int count, float values[]) { assert(count > 0); unsigned int idx; float themax = values[0]; for(i = 1; i < count; ++i) { themax = values[i] > themax ? values[i] : themax; } return themax; }
The following macro can be used with any number and type of arguments, provided that the arguments are ''simple'', i.e. must not contain subexpressions where commas appear (this is because of the way the arguments are counted; the macro can be modified so that it is up to the caller to count the number of arguments passed).
{{works with|GCC}}
#include <stdarg.h> #define MAX(A,...) ({ inline __typeof__ (A) _max_(__typeof__ (A) a, ...) {\ va_list l; int i,c; const char *s = #__VA_ARGS__; __typeof__ (A) max = a;\ __typeof__ (A) t;\ for(c=1;*s!=0;s++) if (*s==',') c++;\ va_start(l, a);\ for(i=0;i<=c;i++) {\ if ((t=va_arg(l,__typeof__ (A))) > max) max = t;\ }\ va_end(l); return max;\ }\ _max_((A),__VA_ARGS__);\ })
C++
A simple wrapper around the standard library function max_element(). Requires C++17.
#include <algorithm> //std::max_element #include <iterator> //std::begin and std::end #include <functional> //std::less template<class It, class Comp = std::less<>> //requires ForwardIterator<It> && Compare<Comp> constexpr auto max_value(It first, It last, Comp compare = std::less{}) { //Precondition: first != last return *std::max_element(first, last, compare); } template<class C, class Comp = std::less<>> //requires Container<C> && Compare<Comp> constexpr auto max_value(const C& container, Comp compare = std::less{}) { //Precondition: !container.empty() using std::begin; using std::end; return max_value(begin(container), end(container), compare); }
C#
C# already has a "Maximum Value" function.
using System.Linq; values.Max();
Clojure
The Clojure.core function max returns the max of its arguments.
(max 1 2 3 4) ; evaluates to 4 ;; If the values are already in a collection, use apply: (apply max [1 2 3 4]) ; evaluates to 4
CMake
Only for lists of integers.
# max(var [value1 value2...]) sets var to the maximum of a list of # integers. If list is empty, sets var to NO. function(max var) set(first YES) set(choice NO) foreach(item ${ARGN}) if(first) set(choice ${item}) set(first NO) elseif(choice LESS ${item}) set(choice ${item}) endif() endforeach(item) set(${var} ${choice} PARENT_SCOPE) endfunction(max) set(list 33 11 44 22 66 55) max(maximum ${list}) message(STATUS "maximum of ${list} => ${maximum}")
-- maximum of 33;11;44;22;66;55 => 66
COBOL
This is already built into the language for tables of numbers.
DISPLAY FUNCTION MAX(nums (ALL))
A sample implementation:
IDENTIFICATION DIVISION.
FUNCTION-ID. greatest-elt.
DATA DIVISION.
LOCAL-STORAGE SECTION.
01 idx USAGE INDEX.
01 Table-Len CONSTANT 50.
LINKAGE SECTION.
01 num-table-area.
03 num-table PIC 9(8) OCCURS Table-Len TIMES.
01 max-elt PIC 9(8).
PROCEDURE DIVISION USING VALUE num-table-area RETURNING max-elt.
PERFORM VARYING idx FROM 1 BY 1 UNTIL idx > Table-Len
IF num-table (idx) > max-elt
MOVE num-table (idx) TO max-elt
END-IF
END-PERFORM
GOBACK
.
END FUNCTION greatest-elt.
CoffeeScript
# using Math library
max1 = (list) ->
Math.max.apply null, list
# using no libraries
max2 = (list) ->
maxVal = list[0]
for value in list
maxVal = value if value > maxVal
maxVal
# Test it
a = [0,1,2,5,4];
alert(max1(a)+". The answer is "+max2(a));
ColdFusion
<Cfset theList = '1, 1000, 250, 13'>
<Cfparam name="maxNum" default=0>
<Cfloop list="#theList#" index="i">
<Cfif i gt maxNum><Cfset maxNum = i></Cfif>
</Cfloop>
<Cfoutput>#maxNum#</Cfoutput>
<Cfset theList = '1, 1000, 250, 13'>
<Cfset maxNum = ListFirst(ListSort(thelist, "numeric", "desc"))>
<Cfoutput>#maxNum#</Cfoutput>
Common Lisp
The built-in Common Lisp function max takes the max of all its arguments.
(max 1 2 3 4) (reduce #'max values) ; find max of a list (loop for x in values maximize x) ; alternative way to find max of a list
Component Pascal
BalckBox Component Builder
MODULE Operations;
IMPORT StdLog,Args,Strings;
PROCEDURE Max(s: ARRAY OF INTEGER): INTEGER;
VAR
i: INTEGER;
max: INTEGER;
BEGIN
max := MIN(INTEGER);
FOR i := 0 TO LEN(s) - 1 DO
max := MAX(max,s[i]);
END;
RETURN max
END Max;
PROCEDURE DoMax*;
VAR
sq: POINTER TO ARRAY OF INTEGER;
p: Args.Params;
i,n,done: INTEGER;
BEGIN
Args.Get(p);
IF p.argc > 0 THEN
NEW(sq,p.argc);
FOR i := 0 TO p.argc - 1 DO
Strings.StringToInt(p.args[i],n,done);
sq[i] := n
END;
StdLog.String("max:> ");StdLog.Int(Max(sq));StdLog.Ln
END
END DoMax;
END Operations.
Execute: ^Q Operations..DoMax 23 12 3 45 34 54 84 ~
{{Out}}
max:> 84
D
D already has a "Maximum Element" function.
void main() { import std.algorithm.searching : maxElement; import std.stdio : writeln; [9, 4, 3, 8, 5].maxElement.writeln; }
{{out}}
9
Dart
/*This is a function which returns the greatest element in a list of numbers */ num findGreatestElement(List<num> list){ num greatestElement = list[0]; for (num element in list){ if (element>greatestElement) { greatestElement = element; } } return greatestElement; } /* and this is a shorter version */ import 'dart:math'; num findGreatestElement(List<num> list){ return list.reduce(max); }
dc
[sm llx] sg
[lm p q] sq
[d lm <u s_ z 0 =q llx] sl
[d sm] su
["Put list of numbers on the stack starting here, then execute g"] s_
3.14159265358979 sp
_275.0 _111.19 0.0 _1234568.0 lp lp _1 *
lgx
{{Out}}
3.14159265358979
DCL
$ list = "45,65,81,12,0,13,-56,123,-123,888,12,0"
$ max = f$integer( f$element( 0, ",", list ))
$ i = 1
$ loop:
$ element = f$element( i, ",", list )
$ if element .eqs. "," then $ goto done
$ element = f$integer( element )
$ if element .gt. max then $ max = element
$ i = i + 1
$ goto loop
$ done:
$ show symbol max
{{out}}
$ @greatest
MAX = 888 Hex = 00000378 Octal = 00000001570
Delphi
program GElemLIst;
{$IFNDEF FPC}
{$Apptype Console}
{$ENDIF}
uses
math;
const
MaxCnt = 10000;
var
IntArr : array of integer;
fltArr : array of double;
i: integer;
begin
setlength(fltArr,MaxCnt); //filled with 0
setlength(IntArr,MaxCnt); //filled with 0.0
randomize;
i := random(MaxCnt); //choose a random place
IntArr[i] := 1;
fltArr[i] := 1.0;
writeln(Math.MaxIntValue(IntArr)); // Array of Integer
writeln(Math.MaxValue(fltArr));
end.
=={{header|Déjà Vu}}==
max lst:
lst! 0
for item in copy lst:
if > item dup:
item drop
!. max [ 10 300 999 9 ]
{{out}}
999
Dyalect
func max(xs) {
var y
for x in xs {
if y == nil || x > y {
y = x
}
}
y
}
var xs = [1..10]
E
This function works for any value which responds to [http://wiki.erights.org/wiki/Category:Message_max/1 max/1]
:
pragma.enable("accumulator") # non-finalized syntax feature
def max([first] + rest) {
return accum first for x in rest { _.max(x) }
}
? max([1, 2, 3])
# value: 3
To require only the comparison protocol, one needs to write out the algorithm a little more explicitly:
def max([var bestSoFar] + rest) {
for x ? (x > bestSoFar) in rest {
bestSoFar := x
}
return bestSoFar
}
? max([1, 3, 2])
# value: 3
? max([[1].asSet(), [2].asSet(), [1, 2].asSet()])
# value: [1, 2].asSet()
EchoLisp
;; a random length list of random values (define L (map random (make-list (random 50) 100))) → L L → (24 60 83 8 24 60 31 97 96 65 9 41 64 24 22 57 73 17 6 28 77 58 18 13 27 22 41 69 85) ;; find max (apply max L) → 97
ECL
MaxVal(SET OF INTEGER s) := MAX(s);
//example usage
SetVals := [4,8,16,2,1];
MaxVal(SetVals) //returns 16;
Efene
list_max = fn ([Head:Rest]) {
list_max(Rest, Head)
}
list_max = fn ([], Res) {
Res
}
fn ([Head:Rest], Max) when Head > Max {
list_max(Rest, Head)
}
fn ([_Head:Rest], Max) {
list_max(Rest, Max)
}
list_max1 = fn ([H:T]) {
lists.foldl(fn erlang.max:2, H, T)
}
@public
run = fn () {
io.format("~p~n", [list_max([9, 4, 3, 8, 5])])
io.format("~p~n", [list_max1([9, 4, 3, 8, 5])])
}
Eiffel
The GREATEST_ELEMENT class:
class
GREATEST_ELEMENT [G -> COMPARABLE]
create
make
feature {NONE} --Implementation
is_max (element: G maximum: G): BOOLEAN
do
Result := maximum >= element
end
max (list: ARRAY [G]): G
require
not_empty: not list.is_empty
do
Result := list [list.lower]
across
list as i
loop
Result := i.item.max (Result)
end
ensure
is_part_of_array: list.has (Result)
is_maximum: list.for_all (agent is_max(?, Result))
end
feature -- Initialization
make
do
end
greatest_element (a: ARRAY [G]): G
do
Result := max (a)
end
end
A test application:
class
APPLICATION
create
make
feature {NONE} -- Initialization
make
-- Run application.
local
numbers: ARRAY [INTEGER]
greatest: GREATEST_ELEMENT [INTEGER]
do
create greatest.make
numbers := <<1, 2, 3, 4, 5, 6, 7, 8, 9>>
print (greatest.greatest_element (numbers))
end
end
Ela
open list
findBy p (x::xs) = foldl (\x y | p x y -> x | else -> y) x xs
maximum = findBy (>)
maximum [1..10]
Elena
ELENA 4.1 :
import extensions;
extension op
{
get Maximal()
{
auto en := cast Enumerator(self.enumerator());
object maximal := nil;
while (en.next())
{
var item := en.get();
if (nil == maximal)
{
maximal := item
}
else if (maximal < item)
{
maximal := item
}
};
^ maximal
}
}
public program()
{
console.printLine(new int[]::(1,2,3,4,20,10,9,8).Maximal)
}
{{out}}
20
Elixir
iex(1)> Enum.max([3,1,4,1,5,9,2,6,5,3]) 9
Emacs Lisp
(defun max (first-arg &rest more-args) (if more-args (let ((max-rest (apply 'max more-args))) (if (> first-arg max-rest) first-arg max-rest)) first-arg))
Example use:
(max 2 7 5) 7
Alternative Built-In:
(cl-loop for el in '(2 7 5) maximize el)
Erlang
Builtin. Using it from the Erlang shell:
lists:max([9,4,3,8,5]).
9
ERRE
PROGRAM MAXLIST
!
! for rosettacode.org
!
! VAR L$,EL$,CH$,I%,MAX
BEGIN
PRINT(CHR$(12);) ! CLS
INPUT("Lista",L$)
L$=L$+CHR$(32)
MAX=-1.7E+38
FOR I%=1 TO LEN(L$) DO
CH$=MID$(L$,I%,1)
IF CH$<>CHR$(32) THEN ! blank is separator
EL$=EL$+CH$
ELSE
IF VAL(EL$)>MAX THEN MAX=VAL(EL$) END IF
EL$=""
END IF
END FOR
PRINT("Max list element is";MAX)
END PROGRAM
Note: The limit of this program is string variable lenght (255 chars). The advantage is no array use.
Euler Math Toolbox
## Euphoria
### Applying a function to each element of an array
```Euphoria
function aeval( sequence sArr, integer id )
for i = 1 to length( sArr ) do
sArr[ i ] = call_func( id, { sArr[ i ] } )
end for
return sArr
end function
object biggun
function biggest( object elem )
if compare(elem, biggun) > 0 then
biggun = elem
end if
return elem
end function
biggun = 0
object a
a = aeval( {1,1234,62,234,12,34,6}, routine_id("biggest") )
printf( 1, "%d\n", biggun )
sequence s
s = {"antelope", "dog", "cat", "cow", "wolf", "wolverine", "aardvark"}
biggun = "ant"
a = aeval( s, routine_id("biggest") )
printf( 1, "%s\n", {biggun} )
{{Out}}
1234
wolverine
More trivial example
function get_biggest(sequence s)
object biggun
biggun = s[1]
for i = 2 to length(s) do
if compare(s[i], biggun) > 0 then
biggun = s[i]
end if
end for
return biggun
end function
constant numbers = {1,1234,62,234,12,34,6}
printf(1,"%d\n",get_biggest(numbers))
constant animals = {"ant", "antelope", "dog", "cat", "cow", "wolf", "wolverine", "aardvark"}
printf(1,"%s\n",{get_biggest(animals)})
{{Out}}
1234
wolverine
Excel
Use the function MAX
=MAX(3;2;1;4;5;23;1;2)
{{out}}
23
=={{header|F_Sharp|F#}}==
I generate a list of 10 random numbers at runtime then use F#'s built in function to find the maximum value of the list.
let N = System.Random() let G = List.init 10 (fun _->N.Next()) List.iter (printf "%d ") G printfn "\nMax value of list is %d" (List.max G)
{{out}}
401566008 1378437959 1806806326 2010005455 1973773308 1216833747 268836584 1963610340 2120237482 1412806752
Max value of list is 2120237482
Factor
The following word is in factor's standard library.
: supremum ( seq -- elt ) [ ] [ max ] map-reduce ;
Fancy
[1,-2,2,4,6,-4,-1,5] max println # => 6
Fantom
Has a built-in method to get maximum from a list.
class Greatest
{
public static Void main ()
{
Int[] values := [1,2,3,4,5,6,7,8,9]
Int greatest := values.max
echo (greatest)
}
}
=={{header|Fōrmulæ}}==
In [https://wiki.formulae.org/Greatest_element_of_a_list this] page you can see the solution of this task.
Fōrmulæ programs are not textual, visualization/edition of programs is done showing/manipulating structures but not text ([http://wiki.formulae.org/Editing_F%C5%8Drmul%C3%A6_expressions more info]). Moreover, there can be multiple visual representations of the same program. Even though it is possible to have textual representation —i.e. XML, JSON— they are intended for transportation effects more than visualization and edition.
The option to show Fōrmulæ programs and their results is showing images. Unfortunately images cannot be uploaded in Rosetta Code.
Forth
: array-max ( addr len -- max )
dup 0= if nip exit then
over @ rot cell+ rot 1-
cells bounds ?do i @ max cell +loop ;
: stack-max ( n ... m count -- max ) 1 ?do max loop ;
Fortran
{{works with|Fortran|2003}}
The intrinsic function maxval returns the maximum value of the elements in an integer or real array:
program test_maxval
integer,dimension(5),parameter :: x = [10,100,7,1,2]
real,dimension(5),parameter :: y = [5.0,60.0,1.0,678.0,0.0]
write(*,'(I5)') maxval(x)
write(*,'(F5.1)') maxval(y)
end program test_maxval
{{Out}}
100
678.0
The intrinsic function max accepts any number of arguments. The type of these arguments can be integer, real, character, string of characters or arrays of these.
program test_max
implicit none
write (*, '(i0)') &
& max (1, 2, 3)
write (*, '(f3.1)') &
& max (1.0, 2.0, 3.0)
write (*, '(a)') &
& max ('a', 'b', 'c')
write (*, '(a)') &
& max ('abc', 'bca', 'cab')
write (*, '(i0, 2 (1x, i0))') &
& max ([1, 8, 6], [7, 5, 3], [4, 2, 9])
write (*, '(f3.1, 2 (1x, f3.1))') &
& max ([1.0, 8.0, 6.0], [7.0, 5.0, 3.0], [4.0, 2.0, 9.0])
write (*, '(a, 2 (1x, a))') &
& max (['a', 'h', 'f'], ['g', 'e', 'c'], ['d', 'b', 'i'])
write (*, '(a, 2 (1x, a))') &
& max (['abc', 'hig', 'fde'], ['ghi', 'efd', 'cab'], ['def', 'bca', 'igh'])
end program test_max
{{Out}}
3
3.0
c
cab
7 8 9
7.0 8.0 9.0
g h i
ghi hig igh
FreeBASIC
' FB 1.05.0 Win64
Function MaxElement(a() As Double) As Double
Dim max As Double = a(LBound(a))
For i As Integer = LBound(a) + 1 To UBound(a)
If a(i) > max Then max = a(i)
Next
Return max
End Function
Dim As Integer i, n
Input "How many values are to be input "; n
If n < 1 Then End
Dim a(1 To n) As Double
For i = 1 To n
Print " Value"; i; " : ";
Input "", a(i)
Next
Dim max As Double = MaxElement(a())
Print
Print "The greatest value is"; max
Print
Print "Press any key to quit"
Sleep
Example of use : {{out}}
How many values are to be input ? 4
Value 1 : 70.5
Value 2 : 23.67
Value 3 : 150.2
Value 4 : 145
The greatest value is 150.2
Frink
println[max[[1,2,3,5,10,20]]]
FunL
Using the pre-defined function max
:
println( max([1,2,3,-1,0]) )
{{out}}
3
It can be implemented as:
def
maximum( xs ) =
def
max( a, b ) = if a <= b then b else a
foldl( f, z, [] ) = z
foldl( f, z, x:xs ) = foldl( f, f(z, x), xs )
foldl1( f, x:xs ) = foldl( f, x, xs )
foldl1( _, [] ) = error( "foldl1: empty list" )
foldl1( max, xs )
Futhark
let main (xs: []f64) = reduce f64.max (-f64.inf) xs
This parallel formulation exploits the fact that negative infinity constitutes a neutral element for the maximum operator.
GAP
# Built-in
L := List([1 .. 100], n -> Random(1, 10));
MaximumList(L);
# 10
Go
;Library
package main import ( "fmt" "github.com/gonum/floats" ) func main() { fmt.Println(floats.Max([]float64{3, 1, 4, 1})) }
{{out}}
4
;List The task title says list. This solution uses a Go slice as a list.
package main import ( "fmt" "math/rand" "time" ) // function, per task description func largest(a []int) (lg int, ok bool) { if len(a) == 0 { return } lg = a[0] for _, e := range a[1:] { if e > lg { lg = e } } return lg, true } func main() { // random size slice rand.Seed(time.Now().UnixNano()) a := make([]int, rand.Intn(11)) for i := range a { a[i] = rand.Intn(101) - 100 // fill with random numbers } fmt.Println(a) lg, ok := largest(a) if ok { fmt.Println(lg) } else { fmt.Println("empty list. no maximum.") } }
;Set The task description says set. This solution uses a Go map as a set.
package main import ( "fmt" "math" "math/rand" "time" ) // Function, per task description. Interesting with the float64 type because // of the NaN value. NaNs do not compare to other values, so the result of // a "largest" function on a set containing a NaN might be open to // interpretation. The solution provided here is to return the largest // of the non-NaNs, and also return a bool indicating the presense of a NaN. func largest(s map[float64]bool) (lg float64, ok, nan bool) { if len(s) == 0 { return } for e := range s { switch { case math.IsNaN(e): nan = true case !ok || e > lg: lg = e ok = true } } return } func main() { rand.Seed(time.Now().UnixNano()) // taking "set" literally from task description s := map[float64]bool{} // pick number of elements to add to set n := rand.Intn(11) // add random numbers, also throw in an occasional NaN or Inf. for i := 0; i < n; i++ { switch rand.Intn(10) { case 0: s[math.NaN()] = true case 1: s[math.Inf(1)] = true default: s[rand.ExpFloat64()] = true } } fmt.Print("s:") for e := range s { fmt.Print(" ", e) } fmt.Println() switch lg, ok, nan := largest(s); { case ok && !nan: fmt.Println("largest:", lg) case ok: fmt.Println("largest:", lg, "(NaN present in data)") case nan: fmt.Println("no largest, all data NaN") default: fmt.Println("no largest, empty set") } }
Golfscript
{$-1=}:max;
[1 4 8 42 6 3]max # Example usage
Groovy
println ([2,4,0,3,1,2,-12].max())
{{Out}}
4
Haskell
The built-in Haskell function maximum returns a maximum based on default comparison between members of an ordered type.
my_max = maximum
It can alternately be defined as a "fold" on the built-in two-argument max function.
my_max = foldl1 max
More generally, '''maximum''' is a special case of '''maximumBy''', which allows us to define or supply our own comparison function, and define the particular type of maximum that we need:
import Data.List (maximumBy) import Data.Ord (comparing) wds :: [String] wds = ["alpha", "beta", "gamma", "delta", "epsilon", "zeta"] main :: IO () main = print $ maximumBy (comparing length) wds
As a fold, maximumBy could be defined along the lines of:
maximumBy :: Foldable t => (a -> a -> Ordering) -> t a -> a maximumBy cmp = let max_ x y = case cmp x y of GT -> x _ -> y in foldr1 max_
hexiscript
fun greatest a
let l len a
let max a[0]
for let i 1; i < l; i++
if max < a[i]
let max a[i]
endif
endfor
return max
endfun
HicEst
max_value = MAX( -123, 234.56, 345.678, -456E3, -455) ! built-in function MAX(...)
! or for an array:
max_value = MAX( array_of_values )
! or to find a maximum value in a file named filename:
CHARACTER List, filename='Greatest element of a list.hic' ! filename contains this script
REAL values(1) ! unknown number of values, allocate more below
OPEN(FIle=filename, BINary, LENgth=len)
ALLOCATE(values, len/2) ! number of values <= half byte count of file
! read all values, returns item count in values_found:
READ(FIle=filename, ItemS=values_found, CLoSe=1) values ! no Format needed for plain text numbers
max_value = MAX(values)
! write values found in filename and result to spreadsheet type dialog window:
DLG(Text=values, Text=max_value, TItle=values_found)
WRITE(ClipBoard, Name) max_value, values_found, values ! pasted to line below
! max_value=345.678; values_found=30; values(1)=-123; values(2)=234.56; values(3)=345.678; values(4)=-456E3; values(5)=-455; values(6)=1; values(7)=2; values(8)=1; values(9)=0; values(10)=0; ...truncated
END
Hoon
:- %say
|= [^ [a=(list ,@) ~] ~]
:- %noun
(snag 0 (sort a gte))
Usage: Add to a file gen/max.hoon
> +max [1 2 3 ~]
3
i
concept largest(l) {
large = l[0]
for element in l
if element > large
large = element
end
end
return large
}
software {
print(largest([23, 1313, 21, 35757, 4, 434, 232, 2, 2342]))
}
=={{header|Icon}} and {{header|Unicon}}==
procedure main()
local l
l := [7,8,6,9,4,5,2,3,1]
write(max(l))
end
procedure max(l)
local max
max := l[1]
every max <:= !l
return max
end
=={{header|IS-BASIC}}==
## J
'''Solution''':
```j> >./</lang
'''Example''':
```J>
./ 1 2 3 2 1
3
>./'' NB. Maximum value of an empty list = identity element (or neutral) of max = -∞
__
Java
The first function works with arrays of floats. Replace with arrays of double, int, or other primitive data type.
public static float max(float[] values) throws NoSuchElementException { if (values.length == 0) throw new NoSuchElementException(); float themax = values[0]; for (int idx = 1; idx < values.length; ++idx) { if (values[idx] > themax) themax = values[idx]; } return themax; }
Optionally, if it is OK to rearrange the contents of the original array:
public static float max(float[] values) throws NoSuchElementException { if (values.length == 0) throw new NoSuchElementException(); Arrays.sort(values);//sorts the values in ascending order return values[values.length-1]; }
The following functions work with Lists or arrays of reference types, respectively. Note that the type is required to implement Comparable, to ensure we can compare them. For Lists, there is a utility method Collections.max() that already does this. For arrays, we can just use the Arrays.asList() wrapper to wrap it into a list and then use the function for lists.
import java.util.List; import java.util.Collections; import java.util.Arrays; public static <T extends Comparable<? super T>> T max(List<T> values) { return Collections.max(values); } public static <T extends Comparable<? super T>> T max(T[] values) { return Collections.max(Arrays.asList(values)); }
JavaScript
===ES3-5===
Math.max.apply(null, [ 0, 1, 2, 5, 4 ]); // 5
ES 5 maxima beyond simple numeric data types
Math.max() serves well with simple numeric types, but for less restricted use we can write a generic '''maximumBy''' function which returns the maximum value from an array containing a series of any consistent data type, and which takes a type-specific comparison function as an argument.
(function () { // (a -> a -> Ordering) -> [a] -> a function maximumBy(f, xs) { return xs.reduce(function (a, x) { return a === undefined ? x : ( f(x, a) > 0 ? x : a ); }, undefined); } // COMPARISON FUNCTIONS FOR SPECIFIC DATA TYPES //Ordering: (LT|EQ|GT) // GT: 1 (or other positive n) // EQ: 0 // LT: -1 (or other negative n) function wordSortFirst(a, b) { return a < b ? 1 : (a > b ? -1 : 0) } function wordSortLast(a, b) { return a < b ? -1 : (a > b ? 1 : 0) } function wordLongest(a, b) { return a.length - b.length; } function cityPopulationMost(a, b) { return a.population - b.population; } function cityPopulationLeast(a, b) { return b.population - a.population; } function cityNameSortFirst(a, b) { var strA = a.name, strB = b.name; return strA < strB ? 1 : (strA > strB ? -1 : 0); } function cityNameSortLast(a, b) { var strA = a.name, strB = b.name; return strA < strB ? -1 : (strA > strB ? 1 : 0); } var lstWords = [ 'alpha', 'beta', 'gamma', 'delta', 'epsilon', 'zeta', 'eta', 'theta', 'iota', 'kappa', 'lambda' ]; var lstCities = [ { name: 'Shanghai', population: 24.15 }, { name: 'Karachi', population: 23.5 }, { name: 'Beijing', population: 21.5 }, { name: 'Tianjin', population: 14.7 }, { name: 'Istanbul', population: 14.4 }, , { name: 'Lagos', population: 13.4 }, , { name: 'Tokyo', population: 13.3 } ]; return [ maximumBy(wordSortFirst, lstWords), maximumBy(wordSortLast, lstWords), maximumBy(wordLongest, lstWords), maximumBy(cityPopulationMost, lstCities), maximumBy(cityPopulationLeast, lstCities), maximumBy(cityNameSortFirst, lstCities), maximumBy(cityNameSortLast, lstCities) ] })();
{{Out}}
[ "alpha", "zeta", "epsilon", { "name": "Shanghai", "population": 24.15 }, { "name": "Tokyo", "population": 13.3 }, { "name": "Beijing", "population": 21.5 }, { "name": "Tokyo", "population": 13.3 } ]
ES6
For, numbers, a method of the standard Math object:
Math.max(...[ 0, 1, 2, 5, 4 ]); // 5
and for orderings defined over other datatypes:
(() => { 'use strict'; // MAXIMUM BY ... -------------------------------------------------------- // Ordering: (LT|EQ|GT): // GT: 1 (or other positive n) // EQ: 0 // LT: -1 (or other negative n) // maximumByMay :: (a -> a -> Ordering) -> [a] -> Maybe a const maximumByMay = (f, xs) => xs.length > 0 ? ( just(xs.slice(1) .reduce((a, x) => f(x, a) > 0 ? x : a, xs[0])) ) : nothing('Empty list'); // GENERIC FUNCTIONS ----------------------------------------------------- // comparing :: (a -> b) -> (a -> a -> Ordering) const comparing = f => (x, y) => { const a = f(x), b = f(y); return a < b ? -1 : a > b ? 1 : 0 }; // catMaybes :: [Maybe a] -> [a] const catMaybes = mbs => concatMap(m => m.nothing ? [] : [m.just], mbs); // concatMap :: (a -> [b]) -> [a] -> [b] const concatMap = (f, xs) => xs.length > 0 ? [].concat.apply([], xs.map(f)) : []; // just :: a -> Just a const just = x => ({ nothing: false, just: x }); // nothing :: () -> Nothing const nothing = (optionalMsg) => ({ nothing: true, msg: optionalMsg }); // show :: Int -> a -> Indented String // show :: a -> String const show = (...x) => JSON.stringify.apply( null, x.length > 1 ? [x[1], null, x[0]] : x ); // TEST ------------------------------------------------------------------ const words = ["alpha", "beta", "gamma", "delta", "epsilon", "zeta", "eta"]; const cities = [{ k: 'Bejing', n: 21.5 }, { k: 'Delhi', n: 16.7 }, { k: 'Karachi', n: 23.5 }, { k: 'Lagos', n: 16.0 }, { k: 'Shanghai', n: 24.3 }, { k: 'Tokyo', n: 13.2 }]; // length :: [a] -> Int const length = xs => xs.length; // population :: {k: String, n: Float} const population = dct => dct.n; // OUTPUT ---------------------------------------------------------------- const maxima = ([ maximumByMay(comparing(length), words), maximumByMay(comparing(length), []), maximumByMay(comparing(population), cities) ]); return show(2, catMaybes(maxima) ); })();
{{Out}}
[
"epsilon",
{
"k": "Shanghai",
"n": 24.3
}
]
jq
jq defines a total ordering of all JSON entities, and the max filter can accordingly be used on any JSON array:
[1, 3, 1.0] | max # => 3
[ {"a": 1}, {"a":3}, {"a":1.0}] | max # => {"a": 3}
Warning: both "[null]|max" and "[]|max" yield null.
Given a stream, s, of JSON values, the following filter will emit null if the stream is empty, or the maximum value otherwise:
reduce s as $x (null; if $x > . then $x else . end)
Julia
Using the built-in maximum
function:
maximum([1,3,3,7])
7
julia> maximum([pi,e+2/5,cos(6)/5,sqrt(91/10)])
3.141592653589793
julia> maximum([1,6,Inf])
Inf
julia> maximum(Float64[])
maximum: argument is empty
at In[138]:1
in maximum at abstractarray.jl:1591
(Note that it throws an exception on an empty array.)
K
|/ 6 1 7 4
7
Klong
list::[ 1.0 2.3 1.1 5.0 3 2.8 2.01 3.14159 77 ]
|/list
|/ [ 1.0 2.3 1.1 5.0 3 2.8 2.01 3.14159 66 ]
|/ 1.0,2.3,1.1,5.0,3,2.8,2.01,3.14159,55
{{out}}
77
66
55
Kotlin
Kotlin already has a 'max' function in its standard library so we use that:
// version 1.0.5-2 fun main(args: Array<String>) { print("Number of values to be input = ") val n = readLine()!!.toInt() val array = DoubleArray(n) for (i in 0 until n) { print("Value ${i + 1} = ") array[i] = readLine()!!.toDouble() } println("\nThe greatest element is ${array.max()}") }
Example of use: {{out}}
Number of values to be input = 4
Value 1 = 70.5
Value 2 = 23.67
Value 3 = 150.2
Value 4 = 145
The greatest element is 150.2
Lasso
define greatest(a::array) => {
return (#a->sort&)->last
}
local(x = array(556,1,7344,4,7,52,22,55,88,122,55,99,1222,578))
greatest(#x)
{{out}}
7344
LFE
Builtin. Using it from the LFE shell:
(: lists max '[9 4 3 8 5])
9
Liberty BASIC
aList$= "1 15 -5 6 39 1.5 14"
maxVal = val(word$(aList$, 1))
token$ = "?"
while token$ <> ""
index = index + 1
token$ = word$(aList$, index)
aVal = val(token$)
if aVal > maxVal then maxVal = aVal
wend
print "maxVal = ";maxVal
Lingo
l = [1,7,5]
put max(l)
-- 7
LiveCode
Max is built-in
put max(2,3,6,7,4,1)
Result: 7
To be fair to the exercise, an alternative implementation could be
function max2 lst
local maxNum
put item 1 of lst into maxNum
repeat with n = 1 to the number of items of lst
if item n of lst > maxNum then
put item n of lst into maxNum
end if
end repeat
return maxNum
end max2
on mouseUp
answer max2("1,2,5,6,7,4,3,2")
end mouseUp
Logo
{{works with|UCB Logo}} If the template is, like SUM, the name of a procedure that is capable of accepting arbitrarily many inputs, it is more efficient to use APPLY instead of REDUCE. The latter is good for associative procedures that have been written to accept exactly two inputs:
to max :a :b
output ifelse :a > :b [:a] [:b]
end
print reduce "max [...]
Alternatively, REDUCE can be used to write MAX as a procedure that accepts any number of inputs, as SUM does:
to max [:inputs] 2
if emptyp :inputs ~
[(throw "error [not enough inputs to max])]
output reduce [ifelse ?1 > ?2 [?1] [?2]] :inputs
end
Logo
{{works with|UCB Logo}}
to bigger :a :b
output ifelse [greater? :a :b] [:a] [:b]
end
to max :lst
output reduce "bigger :lst
end
Logtalk
max([X| Xs], Max) :-
max(Xs, X, Max).
max([], Max, Max).
max([X| Xs], Aux, Max) :-
( X @> Aux ->
max(Xs, X, Max)
; max(Xs, Aux, Max)
).
Lua
-- Table to store values local values = {} -- Read in the first number from stdin local new_val = io.read"*n" -- Append all numbers passed in -- until there are no more numbers (io.read'*n' = nil) while new_val do values[#values+1] = new_val new_val = io.read"*n" end -- Print the max print(math.max(unpack(values)))
M2000 Interpreter
Module TestThis {
Print "Search a tuple type list (is an array also)"
A=(,)
For i=1 to Random(1,10)
Append A, (Random(1,100),)
Next
Print Len(A)
Print A
Print A#max()
Print "Search an array"
B=lambda->Random(1,100)
Rem Dim A(1 to Random(1,10))<<B()
Dim A(1 to Random(1,10))<<lambda->{=Random(1,100)}()
Print Len(A())
Print A()
Print A()#max()
\\ #max() skip non numeric values
Rem Print (1,"100",3)#max()=3
Print "Search an inventory list"
Inventory C
for i=1 to Random(1,10)
do
key=random(10000)
until not exist(c, key)
\\ we can put a number as string
if random(1,2)=1 then Append c, key:=B() else Append c, key:=str$(B())
Next
\\ if inventory item is string with a number work fine
Function MaxItem(a) {
k=each(a,2)
val=a(0!)
while k
\\ using stack of values
\\ over -equal to over 1 - copy value from 1 to top, means double the top value
\\ number - pop top value
\\ drop -equal to drop 1 : drop top value
Push a(k^!): Over : If Number>val then Read Val else drop
Rem If a(k^!)>Val Then Val=a(k^!)
end while
=val
}
Print Len(C)
Print C
Print MaxItem(C)
Print "Search a stack object"
\\ a stack object is the same as the stack of values
\\ which always is present
D=stack
I=0
J=Random(1,10)
\\ Stack stackobjext {}
\\ hide current stack and attach the D stack
Stack D {
Push B() : I++ : IF I>J Else Loop
}
\\ if stack item isn't numeric we get a run time error
Function MaxItemStack(a) {
Stack a {env$=envelope$()}
if replace$("N","", env$)<>"" then error "only numbers allowed"
k=each(a,2)
val=Stackitem(a,1)
while k
If Stackitem(k)>val then Val=stackitem(k)
end while
=val
}
Print Len(D)
Print D
Print MaxItemStack(D)
}
TestThis
Maple
This is a built-in, polymorphic procedure in Maple.
max( { 1, 2, Pi, exp(1) } ); # set
Pi
> max( [ 1, 2, Pi, exp(1) ] ); # list
Pi
> max( 1, 2, Pi, exp(1) ); # sequence
Pi
> max( Array( [ 1, 2, Pi, exp(1) ] ) ); # Array
Pi
For numeric data in (multi-dimensional) rtables, a particularly flexible and powerful method for finding the maximum (and many other things) is the use of "rtable_scanblock". The maximum of an Array is a built-in rtable_scanblock operation and can be found as follows.
A := Array([1,2,4/5,3,11]): rtable_scanblock( A, [rtable_dims(A)], Maximum );
11
=={{header|Mathematica}} / {{header|Wolfram Language}}== Input:
Max[1, 3, 3, 7]
Max[Pi,E+2/5,17 Cos[6]/5,Sqrt[91/10]]
Max[1,6,Infinity]
Max[]
{{Out}}
7
17 Cos[6]/5
Infinity
-Infinity
Note that Max returns minus infinity if supplied with no arguments; as it should:
Max[Max[],Max[a,b,c]]
Max[Max[a],Max[b,c]]
Max[Max[a,b],Max[c]]
Max[Max[a,b,c],Max[]]
should all give the same results, therefore max[] should give -Infinity. If it WOULD give 0 strange this can happen:
Max[Max[], Max[-4, -3]]
WOULD give 0 instead of -3
MATLAB
function [maxValue] = findmax(setOfValues) maxValue = max(setOfValues);
Maxima
u : makelist(random(1000), 50)$
/* Three solutions */
lreduce(max, u);
apply(max, u);
lmax(u);
MAXScript
MAXScript has a built-in function called amax(), which will return the maximum of an array or the values supplied to it. The following custom function will return the maximum of the array supplied to it, or 'undefined' if an empty array is supplied.
fn MaxValue AnArray =
(
if AnArray.count != 0 then
(
local maxVal = 0
for i in AnArray do if i > maxVal then maxVal = i
maxVal
)
else undefined
)
Metafont
The max
macro (in the base set of macro for Metafont) accepts any number of arguments, and accepts both numerics (numbers), pairs (bidimensional vectors), and strings (not mixed).
show max(4,5,20,1);
show max((12,3), (10,10), (25,5));
show max("hello", "world", "Hello World");
min
{{works with|min|0.19.3}}
(
'bool ;does the list have any elements?
(-inf ('> 'pop 'nip if) reduce) ;do if so
({"empty seq" :error "Cannot find the maximum element of an empty sequence" :message} raise) ;do if not
if
) :seq-max
=={{header|МК-61/52}}==
or
<lang>П0 ИП0 С/П - x<0 01 Вx П0 БП 01
=={{header|Modula-3}}==
Modula-3 provides a builtin MAX
function, but it only works on two elements (or enumerations) but not arrays or sets.
We provide a generic Maximum implementation:
GENERIC INTERFACE Maximum(Elem);
EXCEPTION Empty;
PROCEDURE Max(READONLY a: ARRAY OF Elem.T): Elem.T RAISES {Empty};
END Maximum.
GENERIC MODULE Maximum(Elem);
PROCEDURE Max(READONLY arr: ARRAY OF Elem.T): Elem.T RAISES {Empty} =
VAR max := FIRST(Elem.T);
BEGIN
IF NUMBER(arr) = 0 THEN
RAISE Empty;
END;
FOR i := FIRST(arr) TO LAST(arr) DO
IF arr[i] > max THEN
max := arr[i];
END;
END;
RETURN max;
END Max;
BEGIN
END Maximum.
Elem
can be instantiated to any type (any type that can be compared with the '>' function). For convenience Modula-3 provides interfaces/modules for the built in types, like Integer, Real, LongReal, etc, which contain type definitions as well as properties specific to the type.
To make a generic interface/module for a specific type, you must instantiate it:
INTERFACE RealMax = Maximum(Real) END RealMax.
MODULE RealMax = Maximum(Real) END RealMax.
Now we can import RealMax
into our source and use the Max
function:
MODULE Main;
IMPORT RealMax, IO, Fmt;
VAR realarr := ARRAY [1..5] OF REAL {1.1, 1.0, 0.0, 2.4, 3.3};
BEGIN
IO.Put(Fmt.Real(RealMax.Max(realarr)) & "\n");
END Main.
MontiLang
MontiLang has a builtin statement MAX
which finds the maximum of the top two items on the stack. By looping through an array and pushing to the stack, the largest item in an array can be found.
2 5 3 12 9 9 56 2 ARR
LEN VAR l .
0 VAR i .
FOR l
GET i SWAP
i 1 + VAR i .
ENDFOR .
STKLEN 1 - VAR st .
FOR st
MAX
ENDFOR PRINT
Another way to do it.
2 5 3 12 9 9 56 2 ARR
print
LEN VAR l .
0 VAR i .
0
FOR l
swap
GET i rot max
i 1 + VAR i .
ENDFOR
|Greatest number in the list: | out . print
|Press ENTER to exit | input
clear
MUMPS
MV(A,U)
;A is a list of values separated by the string U
NEW MAX,T,I
FOR I=1:1 SET T=$PIECE(A,U,I) QUIT:T="" S MAX=$SELECT(($DATA(MAX)=0):T,(MAX<T):T,(MAX>=T):MAX)
QUIT MAX
Usage:
USER>SET V=","
USER>SET B="-1,-1000,1000,2.3E5,8A,""A"",F"
USER>W $$MV^ROSETTA(B,V)
2.3E5
Neko
/** greatest element from a list (Neko Array) Tectonics: nekoc greatest-element.neko neko greatest-element */ var greatest = function(list) { var max, element; var pos = 1; if $asize(list) > 0 max = list[0]; while pos < $asize(list) { element = list[pos]; if max < element max = element; pos += 1; } return max; } $print(greatest($array(5, 1, 3, 5)), "\n"); $print(greatest($array("abc", "123", "zyx", "def")), "\n");
{{out}}
prompt$ nekoc greatest-element.neko
prompt$ neko ./greatest-element.n
5
zyx
Nemerle
using System;
using Nemerle.Collections;
using System.Linq;
using System.Console;
module SeqMax
{
SeqMax[T, U] (this seq : T) : U
where T : Seq[U]
where U : IComparable
{
$[s | s in seq].Fold(seq.First(), (x, y) => {if (x.CompareTo(y) > 0) x else y})
}
Main() : void
{
def numbers = [1, 12, 3, -5, 6, 23];
def letters = ['s', 'p', 'a', 'm'];
// using SeqMax() method (as task says to "create a function")
WriteLine($"numbers.SeqMax() = $(numbers.SeqMax())");
WriteLine($"letters.SeqMax() = $(letters.SeqMax())");
// using the already available Max() method
WriteLine($"numbers.Max() = $(numbers.Max())");
WriteLine($"letters.Max() = $(letters.Max())")
}
}
{{Out}}
numbers.SeqMax() = 23
letters.SeqMax() = s
numbers.Max() = 23
letters.Max() = s
NetRexx
/* NetRexx */
options replace format comments java crossref savelog symbols binary
rn = Random()
maxElmts = 100
dlist = double[maxElmts]
rlist = Rexx[maxElmts]
loop r_ = 0 to maxElmts - 1
nr = rn.nextGaussian * 100.0
dlist[r_] = nr
rlist[r_] = Rexx(nr)
end r_
say 'Max double:' Rexx(getMax(dlist)).format(4, 9)
say 'Max Rexx:' getMax(rlist).format(4, 9)
return
method getMax(dlist = double[]) public static binary returns double
dmax = Double.MIN_VALUE
loop n_ = 0 to dlist.length - 1
if dlist[n_] > dmax then dmax = dlist[n_]
end n_
return dmax
method getMax(dlist = Rexx[]) public static binary returns Rexx
dmax = Rexx(Double.MIN_VALUE)
loop n_ = 0 to dlist.length - 1
dmax = dlist[n_].max(dmax)
end n_
return dmax
{{Out}}
Max double: 274.457568703
Max Rexx: 274.457568703
NewLISP
(max 1 2 3 5 2 3 4)
(apply max '(1 2 3 5 2 3 4)) ; apply to list
; Added by Nehal-Singhal 2018-05-29
Nial
The behavior of multi-dimensional arrays is like J
max 1 2 3 4
=4
Nim
echo max([2,3,4,5,6,1])
{{out}}
6
=={{header|Oberon-2}}== {{Works with|oo2c Version 2}}
MODULE GreatestElement1;
IMPORT
ADT:ArrayList,
Object:Boxed,
Out;
VAR
a: ArrayList.ArrayList(Boxed.LongInt);
max: Boxed.LongInt;
PROCEDURE Max(al: ArrayList.ArrayList(Boxed.LongInt)): Boxed.LongInt;
VAR
i: LONGINT;
item, max: Boxed.LongInt;
BEGIN
max := NEW(Boxed.LongInt,MIN(LONGINT));
i := 0;
WHILE (i < al.size) DO
item := al.Get(i);
IF item.value > max.value THEN max := item END;
INC(i)
END;
RETURN max
END Max;
BEGIN
a := NEW(ArrayList.ArrayList(Boxed.LongInt),5);
a.Append(NEW(Boxed.LongInt,10));
a.Append(NEW(Boxed.LongInt,32));
a.Append(NEW(Boxed.LongInt,4));
a.Append(NEW(Boxed.LongInt,43));
a.Append(NEW(Boxed.LongInt,9));
max := Max(a);
Out.String("Max: ");Out.LongInt(max.value,4);Out.Ln
END GreatestElement1.
Simple version
MODULE GreatestElement2;
IMPORT
Out;
VAR
a: ARRAY 10 OF LONGINT;
PROCEDURE Max(a: ARRAY OF LONGINT): LONGINT;
VAR
i, max: LONGINT;
BEGIN
max := MIN(LONGINT);
FOR i := 0 TO LEN(a) - 1 DO
IF a[i] > max THEN max := a[i] END;
END;
RETURN max
END Max;
BEGIN
a[0] := 10;
a[1] := 32;
a[2] := 4;
a[3] := 43;
a[4] := 9;
Out.String("Max: ");Out.LongInt(Max(a),4);Out.Ln
END GreatestElement2.
{{out}}(in both programs):
Max: 43
Objeck
The language has a "Max" method for vectors.
values := IntVector->New([4, 1, 42, 5]);
values->Max()->PrintLine();
=={{header|Objective-C}}== {{works with|GNUstep}}
{{works with|Cocoa}}
This code "extends" (through Objective-C categories) the NSArray adding the method
maximumValue
; this one iterates over the objects of the collection
calling the method compare
, if it exists for the object of the
collection. Since normally comparing makes sense between numbers, the code
also check if the objects being compared are of "kind" NSNumber. If one eliminates
this check (substituting it maybe with one that checks if the two object are of
the same "kind"), the code is able to get a maximum value for any objects for
which make sense a compare method (e.g. strings), that must be implemented.
If there's no a known way of comparing two objects of the collection (or if the objects are not "NSNumber"), the the method return nil (the void object).
@interface NSArray (WithMaximum)
- (id)maximumValue;
@end
@implementation NSArray (WithMaximum)
- (id)maximumValue
{
if ( [self count] == 0 ) return nil;
id maybeMax = self[0];
for ( id el in self ) {
if ( [maybeMax respondsToSelector: @selector(compare:)] &&
[el respondsToSelector: @selector(compare:)] &&
[el isKindOfClass: [NSNumber class]] &&
[maybeMax isKindOfClass: [NSNumber class]] ) {
if ( [maybeMax compare: el] == NSOrderedAscending )
maybeMax = el;
} else { return nil; }
}
return maybeMax;
}
@end
This example mixes integers with a double value, just to show that everything is fine until they are NSNumber.
int main()
{
@autoreleasepool {
NSArray *collection = @[@1, @2, @10, @5, @10.5];
NSLog(@"%@", [collection maximumValue]);
}
return 0;
}
OCaml
let my_max = function [] -> invalid_arg "empty list" | x::xs -> List.fold_left max x xs
my_max [4;3;5;9;2;3] ;;
- : int = 9
Octave
Octave's max
accepts a vector (and can return also the index of the maximum value in the vector)
m = max( [1,2,3,20,10,9,8] ); % m = 20
[m, im] = max( [1,2,3,20,10,9,8] ); % im = 4
Oforth
[1, 2.3, 5.6, 1, 3, 4 ] reduce(#max)
Ol
Basics:
; builtin function
(max 1 2 3 4 5) ; 5
(define x '(1 2 3 4 5))
; using to numbers list
(apply max x) ; 5
; using list reducing
(fold max (car x) x) ; 5
; manual lambda-comparator
(print (fold (lambda (a b)
(if (less? a b) b a))
(car x) x)) ; 5
ooRexx
version
-- routine that will work with any ordered collection or sets and bags containing numbers.
::routine listMax
use arg list
items list~makearray -- since we're dealing with different collection types, reduce to an array
if items~isEmpty then return .nil -- return a failure indicator. could also raise an error, if desired
largest = items[1]
-- note, this method does call max one extra time. This could also use the
-- do i = 2 to items~size to avoid this
do item over items
largest = max(item, largest)
end
return largest
version 2 works with any strings
- 30.07.2013 Walter Pachl as for REXX **********************************************************************/ s=.list~of('Walter','lives','in','Vienna') say listMax(s) -- routine that will work with any ordered collection or sets and bags. ::routine listMax use arg list items=list~makearray -- since we're dealing with different collection types, reduce to an array if items~isEmpty then return .nil -- return a failure indicator. could also raise an error, if desired largest = items[1] -- note, this method uses one extra comparison. It could use -- do i = 2 to items~size to avoid this do item over items If item>>largest Then largest = item end return largest
## Oz
```oz
declare
fun {Maximum X|Xr} %% pattern-match on argument to make sure the list is not empty
{FoldL Xr Value.max X} %% fold the binary function Value.max over the list
end
in
{Show {Maximum [1 2 3 4 3]}}
PARI/GP
vecmax(v)
Pascal
See [[Greatest_element_of_a_list#Delphi | Delphi]] {{works with | Free Pascal}} or try this, for it shows the according position
program GElemLIst; {$IFNDEF FPC} {$Apptype Console} {$else} {$Mode Delphi} {$ENDIF} uses sysutils; const MaxCnt = 1000000; type tMaxIntPos= record mpMax, mpPos : integer; end; tMaxfltPos= record mpMax : double; mpPos : integer; end; function FindMaxInt(const ia: array of integer):tMaxIntPos; //delivers the highest Element and position of integer array var i : NativeInt; tmp,max,ps: integer; Begin max := -MaxInt-1; ps := -1; //i = index of last Element i := length(ia)-1; IF i>=0 then Begin max := ia[i]; ps := i; dec(i); while i> 0 do begin tmp := ia[i]; IF max< tmp then begin max := tmp; ps := i; end; dec(i); end; end; result.mpMax := Max; result.mpPos := ps; end; function FindMaxflt(const ia: array of double):tMaxfltPos; //delivers the highest Element and position of double array var i, ps: NativeInt; max : double; tmp : ^double;//for 32-bit version runs faster Begin max := -MaxInt-1; ps := -1; //i = index of last Element i := length(ia)-1; IF i>=0 then Begin max := ia[i]; ps := i; dec(i); tmp := @ia[i]; while i> 0 do begin IF tmp^>max then begin max := tmp^; ps := i; end; dec(i); dec(tmp); end; end; result.mpMax := Max; result.mpPos := ps; end; var IntArr : array of integer; fltArr : array of double; ErgInt : tMaxINtPos; ErgFlt : tMaxfltPos; i: NativeInt; begin randomize; setlength(fltArr,MaxCnt); //filled with 0 setlength(IntArr,MaxCnt); //filled with 0.0 For i := High(fltArr) downto 0 do fltArr[i] := MaxCnt*random(); For i := High(IntArr) downto 0 do IntArr[i] := round(fltArr[i]); ErgInt := FindMaxInt(IntArr); writeln('FindMaxInt ',ErgInt.mpMax,' @ ',ErgInt.mpPos); Ergflt := FindMaxflt(fltArr); writeln('FindMaxFlt ',Ergflt.mpMax:0:4,' @ ',Ergflt.mpPos); end.
Out, because of the searchdirection Position of FindMaxFlt is below FindMaxInt
FindMaxInt 999999 @ 691620
FindMaxFlt 999999.0265 @ 14824
Perl
sub max { my $max = shift; for (@_) { $max = $_ if $_ > $max } return $max; }
It is already implemented in the module List::Util's max() function:
use List::Util qw(max); max(@values);
Perl 6
The built-in function works with any type that defines ordering.
say max 10, 4, 5, -2, 11;
say max <zero one two three four five six seven eight nine>;
# Even when the values and number of values aren't known until runtime
my @list = flat(0..9,'A'..'H').roll((^60).pick).rotor(4,:partial)».join.words;
say @list, ': ', max @list;
{{out|Sample output}}
11
zero
[6808 013C 6D5B 4219 29G9 DC13 CA4F 55F3 AA06 0AGF DAB0 2]: DC13
Phix
?max({1,1234,62,234,12,34,6})
?max({"ant", "antelope", "dog", "cat", "cow", "wolf", "wolverine", "aardvark"})
{{out}}
1234
"wolverine"
PHP
The built-in PHP function max() already does this.
max($values)
PicoLisp
: (max 2 4 1 3) # Return the maximal argument
-> 4
: (apply max (2 4 1 3)) # Apply to a list
-> 4
: (maxi abs (2 -4 -1 3)) # Maximum according to given function
-> -4
PL/I
maximum = A(lbound(A,1));
do i = lbound(A,1)+1 to hbound(A,1);
if maximum < A(i) then maximum = A(i);
end;
PostScript
Ghostscript has a max
built-in:
{{works with|Ghostscript}}
/findmax {
dup 0 get exch % put the first element underneath the array
{max} forall % replace it by the respective larger value if necessary
} def
If not using Ghostscript this gets a bit longer:
/findmax {
dup 0 get exch % put the first element underneath the array
{
dup % duplicate the current item
2 index % duplicate the current maximum value
gt % if the current item is larger
{exch} if % swap the two items so the previous maximum is now the top of the stack
pop % remove it
} forall
} def
{{libheader|initlib}}
[1 2 3 4 5 4 3 2 1] uncons exch {max} fold
PowerBASIC
FUNCTION PBMAIN()
DIM x AS LONG, y AS LONG, z AS LONG
RANDOMIZE TIMER
FOR x = 1 TO 10
y = INT(RND * 10000)
z = MAX(y, z)
NEXT
? STR$(z) & " was the highest value"
END FUNCTION
{{Out}}
8104 was the highest value
PowerShell
The Measure-Object
cmdlet in PowerShell already has this capability:
function Get-Maximum ($a) { return ($a | Measure-Object -Maximum).Maximum }
Prolog
SWI-Prolog already knows max_list.
?- max_list([1, 2, 10, 3, 0, 7, 9, 5], M).
M = 10.
can be implemented like this:
max_list(L, V) :-
select(V, L, R), \+((member(X, R), X > V)).
PureBasic
Procedure.f Max (Array a.f(1))
Protected last, i, ret.f
ret = a(0)
last = ArraySize(a())
For i = 1 To last
If ret < a(i)
ret = a(i)
EndIf
Next
ProcedureReturn ret
EndProcedure
PureBasic: another solution
Procedure.f maxelement(List tl.f())
ForEach tl() : mx.f=mx*Bool(mx>=tl())+tl()*Bool(mx<tl()) : Next
ProcedureReturn mx
EndProcedure
NewList testlist.f() : OpenConsole()
For i=0 To 99 : AddElement(testlist()) : testlist()=Sqr(Random(1000)) : Next
Print("Greatest element = "+StrF(maxelement(testlist()),8)) : Input()
{{out}}
Greatest element = 31.59113884
Python
The built-in Python function max() already does this.
max(values)
Of course this assumes we have a list or tuple (or other sequence like object). (One can even find the ''max()'' or ''min()'' character of a string since that's treated as a sequence of characters and there are "less than" and "greater than" operations (object methods) associate with those characters).
If we truly were receiving a stream of data then in Python, such streams are usually iterable, meaning they have a way of generating one item at a time from the stream.
max(), (and min()), can take iterables and a key argument which takes a function that can transform each item into a type that we can compare, for example, if the stream were returning string representations of integers, one to a line, you could do
floatstrings = ['1\n', ' 2.3\n', '4.5e-1\n', '0.01e4\n', '-1.2']
>>> max(floatstrings, key = float)
'0.01e4\n'
>>>
Normally we would want the converted form as the maximum and we could just as easily write:
max(float(x) for x in floatstrings)
100.0
>>>
Or you can write your own functional version, of the maximum function, using reduce and lambda
mylist = [47, 11, 42, 102, 13]
>>> reduce(lambda a,b: a if (a > b) else b, mylist)
102
Q
q)l:2 9 3 8 4 7
q)max l
9
R
v <- c(1, 2, 100, 50, 0) print(max(v)) # 100
Racket
The "max" function it built in and takes an arbitrary amount of arguments.
(max 12 9 8 17 1)
{{Out}}
17
To use with a list, there is apply:
(apply max '(12 9 8 17 1))
However, if you want to write the function yourself:
(define (my-max l)
(define (max-h l greatest)
(cond [(empty? l) greatest]
[(> (first l) greatest) (max-h (rest l) (first l))]
[else (max-h (rest l) greatest)]))
(if (empty? l) empty (max-h l (first l))))
or with a "for" loop:
(define (my-max l)
(for/fold ([max #f]) ([x l])
(if (and max (> max x)) max x)))
RapidQ
functioni FindMax(...) as double
dim x as integer
for x = 1 to ParamValCount
IF ParamVal(x) > Result THEN Result = ParamVal(x)
next
End functioni
Print FindMax(50, 20, 65, 20, 105)
Rascal
Rascal has a built-in function that gives the greatest element of a list
rascal>import List;
ok
rascal>max([1,2,3,4]);
int: 4
Raven
[ 1 2 3 4 ] max "%d\n" print
{{out}}
4
'''Randomly generated list size and elements'''
100 choose as $cnt
[ ] as $lst
0 $cnt 1 range each drop 100 choose $lst push
$lst print
$lst max "max value: %d\n" print
REBOL
REBOL [
Title: "Maximum Value"
URL: http://rosettacode.org/wiki/Maximum_Value
]
max: func [
"Find maximum value in a list."
values [series!] "List of values."
] [
first maximum-of values
]
print ["Max of" mold d: [5 4 3 2 1] "is" max d]
print ["Max of" mold d: [-5 -4 -3 -2 -1] "is" max d]
{{Out}}
Max of [5 4 3 2 1] is 5
Max of [-5 -4 -3 -2 -1] is -1
Red
Red []
list: [1 2 3 5 4]
print last sort list
REXX
The numbers in the list may be any valid REXX number (integer, negative, floating point, etc.)
using a list
/*REXX program finds the greatest element in a list (of the first 25 reversed primes).*/
$ = reverse(2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97)
say 'list of numbers = ' $ /*show the original list of numbers. */
big=word($, 1) /*choose an initial biggest number. */
# = words($); do j=2 to # /*traipse through the list, find max. */
big=max(big, word($, j) ) /*use the MAX BIF to find the biggie.*/
end /*j*/
say /*stick a fork in it, we're all done. */
say 'the biggest value in a list of ' # " numbers is: " big
{{out|output|text= when using the default (internal) input:}}
list of numbers = 79 98 38 97 37 17 76 16 95 35 74 34 14 73 13 92 32 91 71 31 11 7 5 3 2
the biggest value in a list of 25 numbers is: 98
using an array
/*REXX program finds the greatest element in a list (of the first 25 reversed primes).*/
@.=; @.1 = 2; @.2 = 3; @.3 = 5; @.4 = 7; @.5 =11; @.6 =31; @.7 =71
@.8 =91; @.9 =32; @.10=92; @.11=13; @.12=73; @.13=14; @.14=34
@.15=74; @.16=35; @.17=95; @.18=16; @.19=76; @.20=17; @.21=37
@.22=97; @.23=38; @.24=98; @.25=79
[email protected] /*choose an initial biggest number. */
do #=2 while @.#\=='' /*traipse through whole array of nums. */
big = max(big, @.#) /*use a BIF to find the biggest number.*/
end /*#*/
/*stick a fork in it, we're all done. */
say 'the biggest value in an array of ' #-1 " elements is: " big
{{out|output|text= when using the default (internal) input:}}
the biggest value in an array of 25 elements is: 98
using a list from the terminal
/*REXX program finds the greatest element in a list of numbers entered at the terminal*/
say '────────────────── Please enter a list of numbers (separated by blanks or commas):'
parse pull $; #=words($) /*get a list of numbers from terminal. */
$=translate($, , ',') /*change all commas (,) to blanks. */
big=word($,1); do j=2 to # /*traipse through the list of numbers. */
big=max(big, word($,j)) /*use a BIF for finding the max number.*/
end /*j*/
say /*stick a fork in it, we're all done. */
say '────────────────── The biggest value in the list of ' # " elements is: " big
Programming note: the '''max''' BIF normalizes the number returned (eliding the leading superfluous zeroes).
If this is undesirable, then the '''do''' loop (shown above) can be replaced with:
···; do j=2 to #; _=word($,j)
if _>big then big=_
end /*j*/
{{out|output|text= when using the input from the terminal via a user prompt:}}
────────────────── Please enter a list of numbers (separated by blanks or commas):
-12 -3 0 1.1 1e2 99.2 00245 ◄■■■■■■■■■■ user input
────────────────── The biggest value in the list of 7 elements is: 245
list of any strings
/* REXX ***************************************************************
* If the list contains any character strings, the following will work
* Note the use of >> (instead of >) to avoid numeric comparison
* Note that max() overrides the builtin function MAX
* 30.07.2013 Walter Pachl
**********************************************************************/
list='Walter Pachl living in Vienna'
Say max(list)
list='8 33 -12'
Say max(list)
Exit
max: Procedure
Parse Arg l
max=word(l,1)
Do i=2 To words(l)
If word(l,i)>>max Then
max=word(l,i)
End
Return max
{{out|output|text= when using an '''ASCII''' system:}}
living
8
{{out|output|text= when using an '''EBCDIC''' system:}}
Walter
8
'''output''' when using a ''list'' which is: 12 111111 1 (lexigraphically 12 is greater than 111111)
12
Ring
aList = [1,2,4,5,10,6,7,8,9]
see max(aList)
{{out}}
10
Ruby
max is a method of all Enumerables
## Run BASIC
```Runbasic
list$= "1 12 -55 46 41 3.66 19"
while word$(list$,i+1," ") <> ""
mx = max(mx,val(word$(list$,i+1," ")))
i = i + 1
wend
print mx
Rust
This is built in functionality for everything that can be iterated over. It returns an Option
fn main() { let nums = [1,2,39,34,20]; println!("{:?}", nums.iter().max()); println!("{}", nums.iter().max().unwrap()); }
{{out}}
Some(39)
39
=={{header|S-lang}}==
Starting w/an array, this is trivial:
output:
666
If a is a list instead of an array, then:
<lang S-lang>a = {5, -2, 0, 4, 666, 7};
print(max(list_to_array(a)));
Scala
{{libheader|Scala}}
def noSweat(list: Int*) = list.max // Test assert(noSweat(1, 3, 12, 7) == 12)
Scheme
The built-in Scheme function max takes the max of all its arguments.
(max 1 2 3 4)
(apply max values) ; find max of a list
Seed7
$ include "seed7_05.s7i";
const func integer: max (in array integer: values) is func
result
var integer: max is 0;
local
var integer: index is 0;
begin
max := values[1];
for index range 2 to length(values) do
if values[index] > max then
max := values[index];
end if;
end for;
end func;
const proc: main is func
begin
writeln(max([] (1, 2, 6, 4, 3)));
end func;
{{Out}}
6
Self
Using ''reduceWith:'' it is very simple to find the maximum value among a collection.
(1 & 2 & 3 & 4 & 20 & 10 & 9 & 8) asVector reduceWith: [:a :b | a max: b] "returns 20"
Or, since it's "built-in", you can simply do:
(1 & 2 & 3 & 4 & 20 & 10 & 9 & 8) asVector max. "returns 20"
Sidef
''max'' method returns the greatest element in a list. It works only if the array's elements have the same type (e.g.: strings, numbers).
## Slate
```slate
#(1 2 3 4 20 10 9 8) reduce: [| :a :b | a max: b]
Smalltalk
Using ''fold'' it is very simple to find the maximum value among a collection.
#(1 2 3 4 20 10 9 8) fold: [:a :b | a max: b] "returns 20"
Or, since it's "built-in", you can simply do:
{{works with|Pharo|1.4}} {{works with|Smalltalk/X}}
#(1 2 3 4 20 10 9 8) max. "returns 20"
using #inject:into:
| list |
list := #(1 2 3 4 20 10 9 8).
list inject: (list at: 1) into: [ :number :each |
number max: each ]
SNOBOL4
while a = trim(input) :f(stop)
max = gt(a,max) a :(while)
stop output = max
end
Standard ML
Comparisons are specific for each type. Here is a max function for a list of ints:
fun max_of_ints [] = raise Empty
| max_of_ints (x::xs) = foldl Int.max x xs
- max_of_ints [4,3,5,9,2,3]; val it = 9 : int
Stata
Use the '''[https://www.stata.com/help.cgi?summarize summarize]''' command to compute the maximum value of a variable:
qui sum x
di r(max)
Mata has also several [https://www.stata.com/help.cgi?mf_minmax functions] to compute minimum or maximum of a vactor or matrix:
a = 1,5,3,4,2,7,9,8
max(a)
Swift
{{works with|Swift|2.x}}
if let x = [4,3,5,9,2,3].maxElement() { print(x) // prints 9 }
{{works with|Swift|1.x}}
let x = maxElement([4,3,5,9,2,3]) println(x) // prints 9
Tailspin
templates max
@: $(1);
$(2..-1)... -> #
$@!
<$@..> @: $;
end max
[1, 5, 20, 3, 9, 7] -> max -> !OUT::write
// outputs 20
Can also be written as an inline templates
[1, 5, 20, 3, 9, 7] -> (@: $(1); $(2..-1)... -> # $@ ! <$@..> @: $;) -> !OUT::write
// outputs 20
Or we can do just the matching in an inline templates referencing the outer state
templates max
@: $(1);
$(2..-1)... -> (<$@max..> @max: $;) -> !VOID
$@!
end max
[1, 5, 20, 3, 9, 7] -> max -> !OUT::write
// outputs 20
Tcl
{{works with|Tcl|8.5}}
Use the {*}
expansion operator to substitute the list value with its constituent elements
package require Tcl 8.5 set values {4 3 2 7 8 9} ::tcl::mathfunc::max {*}$values ;# ==> 9
=={{header|TI-83 BASIC}}==
The builtin max
function can be applied to lists. max({1, 3, 2
.
=={{header|TI-89 BASIC}}==
The builtin max
function can be applied to lists. max({1, 3, 2})
= 3.
Trith
[1 -2 3.1415 0 42 7] [max] foldl1
TUSCRIPT
$$ MODE TUSCRIPT
LOOP n,list="2'4'0'3'1'2'-12"
IF (n==1) greatest=VALUE(list)
IF (list>greatest) greatest=VALUE(list)
ENDLOOP
PRINT greatest
{{Out}}
4
uBasic/4tH
Since uBasic/4tH has a stack, it's only logical to use it.
_FNmax Param(1) Local(3)
d@ = -(2^31) ' Set maximum to a tiny value
For b@ = 1 To a@ ' Get all values from the stack c@ = Pop() If c@ > d@ THEN d@ = c@ ' Change maximum if required Next Return (d@) ' Return the maximum
## UNIX Shell
{{works with|bash|3}}
{{works with|pdksh}}
```bash
max() {
local m=$1
shift
while [ $# -gt 0 ]
do
[ "$m" -lt "$1" ] && m=$1
shift
done
echo "$m"
}
max 10 9 11 57 1 12
{{works with|Bourne Shell}}
max() { m=$1 # Bourne Shell has no local command. shift while [ $# -gt 0 ] do [ "$m" -lt "$1" ] && m=$1 shift done echo "$m" }
Ursa
The max
function:
def max (int<> list)
decl int max i
set max list<0>
for (set i 1) (< i (- (size list) 1)) (inc i)
if (> list<i> max)
set max list<i>
end if
end for
return max
end max
In use: (assuming the function is in the file max.u
)
cygnus/x ursa v0.75 (default, release 0)
[Oracle Corporation JVM 1.8.0_51 on Mac OS X 10.10.5 x86_64]
> import "max.u"
> decl int<> list
> append 5 1 7 3 9 2 list
> out (max list) endl console
9
> _
Ursala
The built-in $^
operator takes a binary predicate of any type to a
function extracting the maximum value from a non-empty list of that type. In this
case it is used with fleq
, the partial order relation on floating point
numbers.
#import flo
#cast %e
example = fleq$^ <-1.,-2.,0.,5.,4.,6.,1.,-5.>
{{Out}}
6.000000e+00
V
Assuming it is a list of positive numbers
[4 3 2 7 8 9] 0 [max] fold
=9
If it is not
[4 3 2 7 8 9] dup first [max] fold
=9
VBA
Option Explicit
Sub Main()
Dim a
a = Array(1, 15, 19, 25, 13, 0, -125, 9)
Debug.Print Max_VBA(a)
End Sub
Function Max_VBA(Arr As Variant) As Long
Dim i As Long, temp As Long
temp = Arr(LBound(Arr))
For i = LBound(Arr) + 1 To UBound(Arr)
If Arr(i) > temp Then temp = Arr(i)
Next i
Max_VBA = temp
End Function
{{Out}}
25
VBScript
Function greatest_element(arr)
tmp_num = 0
For i = 0 To UBound(arr)
If i = 0 Then
tmp_num = arr(i)
ElseIf arr(i) > tmp_num Then
tmp_num = arr(i)
End If
Next
greatest_element = tmp_num
End Function
WScript.Echo greatest_element(Array(1,2,3,44,5,6,8))
{{Out}}
44
Vim Script
for numbers (not floats):
max([1, 3, 2])
result: 3
for strings (with configurable ignore-case):
function! Max(list, ...) " {list} list of strings " {a:1} 'i': ignore case, 'I': match case, otherwise use 'ignorecase' option if empty(a:list) return 0 endif let gt_op = a:0>=1 ? get({'i': '>?', 'I': '>#'}, a:1, '>') : '>' let cmp_expr = printf('a:list[idx] %s maxval', gt_op) let maxval = a:list[0] let len = len(a:list) let idx = 1 while idx < len if eval(cmp_expr) let maxval = a:list[idx] endif let idx += 1 endwhile return maxval endfunction
Visual Basic
Public Function ListMax(anArray())
'return the greatest element in array anArray
'use LBound and UBound to find its length
n0 = LBound(anArray)
n = UBound(anArray)
theMax = anArray(n0)
For i = (n0 + 1) To n
If anArray(i) > theMax Then theMax = anArray(i)
Next
ListMax = theMax
End Function
Public Sub ListMaxTest()
Dim b()
'test function ListMax
'fill array b with some numbers:
b = Array(5992424433449#, 4534344439984#, 551344678, 99800000#)
'print the greatest element
Debug.Print "Greatest element is"; ListMax(b())
End Sub
Result:
ListMaxTest
Greatest element is 5992424433449
Wart
Wart defines max
in terms of the more general best
.
def (best f seq) if seq ret winner car.seq each elem cdr.seq if (f elem winner) winner <- elem def (max ... args) (best (>) args)
(>)
is >
while suppressing infix expansion.
WDTE
import 'stream';
let a => import 'arrays';
let max list =>
a.stream list
-> s.extent 1 >
-> at 0
;
extent
is a standard library function that returns a sorted list of the elements of a stream that fit the given function best, so >
results in the maximum element.
Wortel
The @maxl
returns the maximum value of a list:
@maxl [1 6 4 6 4 8 6 3] ; returns 8
XPL0
The set of values is the lengths of the lines of text in the input file.
include c:\cxpl\codes; \include 'code' declarations
def Tab=$09, LF=$0A, CR=$0D, EOF=$1A;
int CpuReg, Hand;
char CmdTail($80);
int I, Max, C;
[\Copy file name on command line, which is in the Program Segment Prefix (PSP)
\ ES=CpuReg(11), to the CmdTail array, which is in our Data Segment = CpuReg(12)
CpuReg:= GetReg; \point to copy of CPU registers
Blit(CpuReg(11), $81, CpuReg(12), CmdTail, $7F);
Hand:= FOpen(CmdTail, 0); \open file for input and get its handle
FSet(Hand, ^I); \assign handle to device 3
OpenI(3); \initialize file for input
Max:= 0; \scan file for longest line
repeat I:= 0;
repeat C:= ChIn(3);
case C of
CR, LF, EOF: []; \don't count these characters
Tab: [I:= I+8 & ~7] \(every 8th column)
other I:= I+1; \count all other characters
until C=LF or C=EOF;
if I > Max then Max:= I;
until C = EOF;
Text(0, "Longest line = "); IntOut(0, Max); CrLf(0);
]
Example of running the program on its source code:
maxline maxline.xpl
Longest line = 80
XSLT
The desired value is the first in a sequence that has been sorted numerically in descending order.
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"> <xsl:output method="text"/> <xsl:template match="/"> <xsl:for-each select="/*/*"> <!-- without data-type="number", items are sorted alphabetically --> <xsl:sort data-type="number" order="descending"/> <xsl:if test="position() = 1"> <xsl:value-of select="."/> </xsl:if> </xsl:for-each> </xsl:template> </xsl:stylesheet>
Sample input:
<number>3</number>
<number>1</number>
<number>12</number>
<number>7</number>
</numbers>
{{Out}}
12
Yabasic
l$ = "1,1234,62,234,12,34,6"
dim n$(1)
n = token(l$, n$(), ", ")
for i = 1 to n
t$ = n$(i)
if t$ > m$ then m$ = t$ end if // or: if t$ > m$ m$ = t$
if val(t$) > m then m = val(t$) end if // or: if val(t$) > m m = val(t$)
next
print "Alphabetic order: ", m$, ", numeric order: ", m
Yacas
Input:
Max({1, 3, 3, 7})
Max({Pi,Exp(1)+2/5,17*Cos(6)/5,Sqrt(91/10)})
Max({1,6,Infinity})
Max({})
{{Out}}
7
(17*Cos(2*Pi-6))/5
Infinity
Undefined
Yorick
The built-in function ''max'' does this. Interactive example:
> foo = [4, 3, 2, 7, 8, 9]
> max(foo)
9
zkl
(1).max(1,2,3) //-->3
(66).max(1,2,3.14) //-->66
If given a list, the max of the list is returned. The number/object just selects the method to call. Notice the difference between Int.max and Float.max.
(66).max(T(1,2,3)) //-->3
(66).max(T(1,2,3.14)) //-->3
(6.6).max(T(1,2,3.14)) //-->3.14
For other object types, you could use:
fcn max{ vm.arglist.reduce(fcn(p,n){ if(p < n) n else p }) }
max(2,1,-40,50,2,4,2) //-->50
max(2) //-->2
max("foo","bar") //-->"foo"
max("3",4,"5") //-->"5" only if strings contain only digits
ZX Spectrum Basic
10 PRINT "Values"''
20 LET z=0
30 FOR x=1 TO INT (RND*10)+1
40 LET y=RND*10-5
50 PRINT y
60 LET z=(y AND y>z)+(z AND y<z)
70 NEXT x
80 PRINT '"Max. value = ";z