Опис

array_filter(array $array, ?callable $callback = null, int $mode = 0): array

Iterates over each value in the array passing them to the callback function. If the callback function returns true, the current value from array is returned into the result array.

Array keys are preserved, and may result in gaps if the array was indexed. The result array can be reindexed using the array_values() function.

Параметри

array

The array to iterate over

callback

The callback function to use

If no callback is supplied, all empty entries of array will be removed. See empty() for how PHP defines empty in this case.

mode

Flag determining what arguments are sent to callback:

ARRAY_FILTER_USE_KEY - pass key as the only argument to callback instead of the value
ARRAY_FILTER_USE_BOTH - pass both value and key as arguments to callback instead of the value

Default is 0 which will pass value as the only argument to callback instead.

Значення, що повертаються

Returns the filtered array.

Журнал змін

Версія	Опис
8.0.0	`callback` is nullable now.
8.0.0	Тепер функція видасть `E_WARNING`, якщо `callback` очікує параметр за посиланням.

Приклади

Приклад #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 = ['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5];
$array2 = [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"));
?>

Поданий вище приклад виведе:

Odd :
Array
(
    [a] => 1
    [c] => 3
    [e] => 5
)
Even:
Array
(
    [0] => 6
    [2] => 8
    [4] => 10
    [6] => 12
)

Приклад #2 array_filter() without callback

<?php

$entry = [
    0 => 'foo',
    1 => false,
    2 => -1,
    3 => null,
    4 => '',
    5 => '0',
    6 => 0,
];

print_r(array_filter($entry));
?>

Поданий вище приклад виведе:

Array
(
    [0] => foo
    [2] => -1
)

Приклад #3 array_filter() with mode

<?php

$arr = ['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4];

var_dump(array_filter($arr, function($k) {
    return $k == 'b';
}, ARRAY_FILTER_USE_KEY));

var_dump(array_filter($arr, function($v, $k) {
    return $k == 'b' || $v == 4;
}, ARRAY_FILTER_USE_BOTH));
?>

Поданий вище приклад виведе:

array(1) {
  ["b"]=>
  int(2)
}
array(2) {
  ["b"]=>
  int(2)
  ["d"]=>
  int(4)
}

Примітки

Застереження

If the array is changed from the callback function (e.g. element added or unset) the behavior of this function is undefined.

Прогляньте також

array_intersect() - Computes the intersection of arrays
array_find() - Returns the first element satisfying a callback function
array_any() - Checks if at least one array element satisfies a callback function
array_map() - Застосовує зворотній виклик до всіх елементів зазначених масивів
array_reduce() - Iteratively reduce the array to a single value using a callback function