PHP array_filter()Functions

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Examples

Filter array elements with a callback function:

<?php function test_odd($var) { return($var & 1); } $a1=array("a","b",2,3,4); print_r(array_filter($a1,"test_odd")); ?>

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Definition and Usage

The array_filter() function filters the elements of an array using a callback function.

This function passes each value in the input array to the callback function. If the callback function returns true, the current value from the input array is returned into the result array. Array keys are preserved.

Syntax

array array_filter ( array $array [, callable $callback [, int $flag = 0 ]] )

Parameters Description
array Required. Specifies the array to filter.
callback Optional. Specifies the callback function to use.
flag

Optional. Determines the argument format that the callback accepts:

  • ARRAY_FILTER_USE_KEY - callback accepts the key as the only argument
  • ARRAY_FILTER_USE_BOTH - callback accepts both key and value

Technical Details

Return value: Returns the filtered array.
PHP Version: 4.0.6+

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