array_keys
Return all the keys or a subset of the keys of an array
Description
array array_keys(array $array)
array array_keys(array $array, mixed $filter_value, bool $strict = false)
If a filter_value is specified,
then only the keys for that value are returned. Otherwise, all
the keys from the array are returned.
Parameters
-
array
-
An array containing keys to return.
-
filter_value
-
If specified, then only keys containing this value are returned.
-
strict
-
Determines if strict comparison (===) should be used during the search.
Return Values
Returns an array of all the keys in array.
Examples
Example #1 array_keys example
<?php
$array = array(0 => 100, "color" => "red");
print_r(array_keys($array));
$array = array("blue", "red", "green", "blue", "blue");
print_r(array_keys($array, "blue"));
$array = array("color" => array("blue", "red", "green"),
"size" => array("small", "medium", "large"));
print_r(array_keys($array));
?>
The above example will output:
Array
(
[0] => 0
[1] => color
)
Array
(
[0] => 0
[1] => 3
[2] => 4
)
Array
(
[0] => color
[1] => size
)
See Also
- array_values
- array_combine
- array_key_exists
- array_search