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Benjamin Crouzier
Benjamin Crouzier

Reputation: 41905

Change all values of an array without a loop construct

I have the following array in php:

$a = [0, 4, 5, 7];

I would like to increment all the values without writing a loop (for, foreach...)

// increment all values
// $a is now array(1, 5, 6, 8)

Is it possible in php?

And by extention, is it possible to call a function on each element and replace that element by the return value of the function?

For example:

$a = doubleValues($a); // array(0, 8, 10, 14)

Upvotes: 26

Views: 44337

Answers (3)

Rubberducker
Rubberducker

Reputation: 1137

Yeah this is possible using the PHP function array_map() as mentioned in the other answers.This solutions are completely right und useful. But you should consider, that a simple foreach loop will be faster and less memory intense. Furthermore it grants a better readability for other programmers and users. Nearly everyone knows, what a foreach loop is doing and how it works, but most PHP users are not common with the array_map() function.

Upvotes: 9

Michael Berkowski
Michael Berkowski

Reputation: 270637

This is a job for array_map() (which will loop internally):

$a = array(0, 4, 5, 7);
// PHP 5.3+ anonmymous function.
$output = array_map(function($val) { return $val+1; }, $a);

print_r($output);
Array
(
    [0] => 1
    [1] => 5
    [2] => 6
    [3] => 8
)

Edit by OP:

function doubleValues($a) {
  return array_map(function($val) { return $val * 2; }, $a);
}

Upvotes: 65

Teena Thomas
Teena Thomas

Reputation: 5239

$arr = array(0, 4, 5, 7);
function val($val) { return $val+1; }
$arr = array_map( 'val' , $arr );
print_r( $arr );

See it here

Upvotes: 1

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