Apply a callback to an array: Difference between revisions

<actionscript>

</actionscript>

<ada>with Ada.Text_Io;

end Call_Back_Example;</ada>

#ifndef __CALLBACK_H

#define __CALLBACK_H

/*

* By declaring the function in a separate file, we allow

* it to be used by other source files.

*

* It also stops ICC from complaining.

*

* If you don't want to use it outside of callback.c, this

* file can be removed, provided the static keyword is prepended

* to the definition.

*/

void map(int* array, int len, void(*callback)(int,int));

#endif

#include <stdio.h>

#include "callback.h"

/*

* We don't need this function outside of this file, so

* we declare it static.

*/

static void callbackFunction(int location, int value)

printf("array[%d] = %d\n", location, value);

}

void map(int* array, int len, void(*callback)(int,int))

{

int i;

for(i = 0; i < len; i++)

{

callback(i, array[i]);

}

}

int main()

{

int array[] = { 1, 2, 3, 4 };

map(array, 4, callbackFunction);

return 0;

#include <iostream> //cout for printing

#include <algorithm> //for_each defined here

//create the function (print the square)

void print_square(int i) {

std::cout << i*i << " ";

}

int main() {

//create the array

int ary[]={1,2,3,4,5};

//stl for_each

std::for_each(ary,ary+5,print_square);

return 0;

}

//prints 1 4 9 16 25

#include <iostream> //cout for printing

#include <algorithm> //for_each defined here

#include <vector> //stl vector class

//create the function (print the square)

void print_square(int i) {

std::cout << i*i << " ";

}

int main() {

//create the array

std::vector<int> ary;

ary.push_back(1);

ary.push_back(2);

ary.push_back(3);

ary.push_back(4);

ary.push_back(5);

//stl for_each

std::for_each(ary.begin(),ary.end(),print_square);

return 0;

}

//prints 1 4 9 16 25

#include <iostream> //cout for printing

#include <algorithm> //for_each defined here

#include <vector> //stl vector class

#include <functional> //bind and ptr_fun

//create a binary function (print any two arguments together)

template<class type1,class type2>

void print_juxtaposed(type1 x, type2 y) {

std::cout << x << y;

}

int main() {

//create the array

std::vector<int> ary;

ary.push_back(1);

ary.push_back(2);

ary.push_back(3);

ary.push_back(4);

ary.push_back(5);

//stl for_each, using binder and adaptable unary function

std::for_each(ary.begin(),ary.end(),std::bind2nd(std::ptr_fun(print_juxtaposed<int,std::string>),"x "));

return 0;

}

//prints 1x 2x 3x 4x 5x

using namespace std;

using namespace boost::lambda;

vector<int> ary(10);

int i = 0;

for_each(ary.begin(), ary.end(), _1 = ++var(i)); // init array

transform(ary.begin(), ary.end(), ostream_iterator<int>(cout, " "), _1 * _1); // square and output

(map nil #'print #(1 2 3 4 5))

(defun square (x) (* x x))

(map 'vector #'square #(1 2 3 4 5))

(defvar *a* (vector 1 2 3))

(map-into *a* #'1+ *a*)

<d>U[] map(T, U)(T[] array, U delegate(T) dg) {

}</d>

<d>writefln(map!("a + 5")([1, 2, 3, 4, 5]));</d>

module arrCallback

contains

elemental function cube( x )

implicit none

real :: cube

real, intent(in) :: x

cube = x * x * x

end function cube

end module arrCallback

program testAC

use arrCallback

implicit none

integer :: i, j

real, dimension(3,4) :: b, &

a = reshape( (/ ((10 * i + j, i = 1, 3), j = 1, 4) /), (/ 3,4 /) )

do i = 1, 3

write(*,*) a(i,:)

end do

b = cube( a ) ! Applies CUBE to every member of a,

! and stores each result in the equivalent element of b

do i = 1, 3

write(*,*) b(i,:)

end do

end program testAC

program test

C

C-- Declare array:

integer a(5)

C

C-- Fill it with Data

data a /45,22,67,87,98/

C

C-- Do something with all elements (in this case: print their squares)

do i=1,5

print *,a(i)*a(i)

end do

C

end

let square x = x*x

let values = [1..10]

map square values

[square x | x <- values]

let printSquares = putStr.unlines.map (show.square)

printSquares values

import Data.Array.IArray

let square x = x*x

let values = array (1,10) [(i,i)|i <- [1..10]] :: Array Int Int

amap square values

<java>interface IntToVoid {

}</java>

<java>interface IntToInt {

}</java>

function map(a, func) {

for (var i in a)

a[i] = func(a[i]);

}

var a = [1, 2, 3, 4, 5];

map(a, function(v) { return v * v; });

var a = (1).to(10).collect(Math.pow.curry(undefined,2));

function cube(num) {

return Math.pow(num, 3);

}

var numbers = [1, 2, 3, 4, 5];

//get results of calling cube on every element

var cubes1 = numbers.map(cube);

//display each result in a separate dialog

cubes1.forEach(alert);

//array comprehension

var cubes2 = [cube(n) for each (n in numbers)];

var cubes3 = [n * n * n for each (n in numbers)];

{{libheader|Functional}}

Functional.map('x*x*x', [1,2,3,4,5])

Array.map

let square x = x * x;;

let values = Array.init 10 ((+) 1);;

Array.map square values;;

end</pre>

# create array

my @a = (1, 2, 3, 4, 5);

# create callback function

sub mycallback {

return 2 * shift;

}

# use array indexing

my $i;

for ($i = 0; $i < scalar @a; $i++) {

print "mycallback($a[$i]) = ", mycallback($a[$i]), "\n";

}

# using foreach

foreach my $x (@a) {

print "mycallback($x) = ", mycallback($x), "\n";

}

# using map (useful for transforming an array)

my @b = map mycallback($_), @a; # @b is now (2, 4, 6, 8, 10)

# and the same using an anonymous function

my @c = map { $_ * 2 } @a; # @c is now (2, 4, 6, 8, 10)

# use a callback stored in a variable

my $func = \&mycallback;

my @d = map $func->($_), @a; # @d is now (2, 4, 6, 8, 10)

function cube($n)

{

return($n * $n * $n);

}

$a = array(1, 2, 3, 4, 5);

$b = array_map("cube", $a);

print_r($b);

set serveroutput on

declare

type myarray is table of number index by binary_integer;

x myarray;

i pls_integer;

begin

-- populate array

for i in 1..5 loop

x(i) := i;

end loop;

i :=0;

-- square array

loop

i := i + 1;

begin

x(i) := x(i)*x(i);

dbms_output.put_line(x(i));

exception

when no_data_found then exit;

end;

end loop;

end;

/

<python>

</python>

<python>print " ".join(str(n * n) for n in range(10))</python>

<python>print " ".join(map(str, map(square, range(10))))</python>

<python>0 1 4 9 16 25 36 49 64 81</python>

# You could use a traditional "for i in arr" approach like below:

for i in [1,2,3,4,5] do

puts i**2

end

# Or you could the more preferred ruby way of an iterator (which is borrowed from SmallTalk)

[1,2,3,4,5].each{ |i| puts i**2 }

# To create a new array of each value squared

[1,2,3,4,5].map{ |i| i**2 }

(define (square n) (* n n))

(define x #(1 2 3 4 5))

(map square (vector->list x))

(map (lambda (n) (* n n)) '(1 2 3 4 5))

(define (map f L)

(if (null? L)

L

(cons (f (car L)) (map f (cdr L)))))

foreach var $dat { myfunc $var }

foreach name [array names dat] { myfunc $dat($name) }