Filters elements of an array using a callback function array_fill array_flip Array Functions PHP Manual array_filter (PHP 4 >= 4.0.6, PHP 5)array_filter — Filters elements of an array using a callback function Description array array_filter ( array $input [, callback $callback ] ) Iterates over each value in the input array passing them to the callback function. If the callback function returns true, the current value from input is returned into the result array. Array keys are preserved. Parameters input The array to iterate over callback The callback function to use If no callback is supplied, all entries of input equal to FALSE (see converting to boolean) will be removed. Return Values Returns the filtered array. Examples Example #1 array_filter() example <?phpfunction odd($var){ return($var & 1);}function even($var){ return(!($var & 1));}$array1 = array("a"=>1, "b"=>2, "c"=>3, "d"=>4, "e"=>5);$array2 = array(6, 7, 8, 9, 10, 11, 12);echo "Odd :\n";print_r(array_filter($array1, "odd"));echo "Even:\n";print_r(array_filter($array2, "even"));?> The above example will output: Odd : Array ( [a] => 1 [c] => 3 [e] => 5 ) Even: Array ( [0] => 6 [2] => 8 [4] => 10 [6] => 12 ) Example #2 array_filter() without callback <?php$entry = array( 0 => 'foo', 1 => false, 2 => -1, 3 => null, 4 => '' );print_r(array_filter($entry));?> The above example will output: Array ( [0] => foo [2] => -1 ) Notes Caution If the array is changed from the callback function (e.g. element added, deleted or unset) the behavior of this function is undefined. See Also array_map() array_reduce() array_walk() array_fill array_flip Array Functions PHP Manual
