(PHP 4 >= 4.0.6, PHP 5)
array_filter — Filters elements of an array using a callback function
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.
The array to iterate over
The callback function to use
If no callback is supplied, all entries of input equal to FALSE (see converting to boolean) will be removed.
Returns the filtered array.
Example #1 array_filter() example
<?php
function odd($var)
{
// returns whether the input integer is odd
return($var & 1);
}
function even($var)
{
// returns whether the input integer is even
return(!($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
)
If the array is changed from the callback function (e.g. element added, deleted or unset) the behavior of this function is undefined.