array_filter
(PHP 4 >= 4.0.6)
array_filter --
Filters elements of an array using a callback function
Description
array
array_filter ( array input [, callback function])
array_filter() returns an array
containing all the elements of input
filtered according a callback function. If the
input is an associative array
the keys are preserved.
Example 1. array_filter() example function odd($var) {
return ($var % 2 == 1);
}
function even($var) {
return ($var % 2 == 0);
}
$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 printout of the program above will be:
Odd :
Array
(
[a] => 1
[c] => 3
[e] => 5
)
Even:
Array
(
[0] => 6
[2] => 8
[4] => 10
[6] => 12
) |
|
Users may not change the array itself from the callback
function. e.g. Add/delete an element, unset the array that
array_filter() is applied to. If the array
is changed, the behavior of this function is undefined.
See also array_map() and
array_reduce().