array_keys
Description
The array_keys of Array for PHP return all the keys or a subset of the keys of an array.
Syntax
array_keys(
array $array
): arrayarray_keys(
array $array,
mixed $filter_value,
bool $strict = false
): arrayParameters
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
Returns an array of all the keys in array.
Examples
1 · array · Indexed
<? $array = array(null, false, true, 0, 1); $return = array_keys($array); print_r($return); ?>
Array
(
[0] => 0
[1] => 1
[2] => 2
[3] => 3
[4] => 4
)
2 · array · Associative
<?
$array = array(
"a" => null,
"b" => false,
"c" => true,
"d" => 0,
"e" => 1
);
$return = array_keys($array);
print_r($return);
?>Array
(
[0] => a
[1] => b
[2] => c
[3] => d
[4] => e
)
3 · filter_value · Indexed
<? $array = array(null, false, true, 0, 1); $filter_value = 1; $return = array_keys($array, $filter_value); print_r($return); ?>
Array
(
[0] => 2
[1] => 4
)
4 · filter_value · Associative
<?
$array = array(
"a" => null,
"b" => false,
"c" => true,
"d" => 0,
"e" => 1
);
$filter_value = 1;
$return = array_keys($array, $filter_value);
print_r($return);
?>Array
(
[0] => c
[1] => e
)
5 · strict · Indexed
<? $array = array(null, false, true, 0, 1); $filter_value = 1; $strict = true; $return = array_keys($array, $filter_value, $strict); print_r($return); ?>
Array
(
[0] => 4
)
6 · strict · Associative
<?
$array = array(
"a" => null,
"b" => false,
"c" => true,
"d" => 0,
"e" => 1
);
$filter_value = 1;
$strict = true;
$return = array_keys($array, $filter_value, $strict);
print_r($return);
?>Array
(
[0] => e
)
Links
Array
- array
- array_change_key_case
- array_chunk
- array_column
- array_combine
- array_count_values
- array_diff
- array_diff_assoc
- array_diff_key
- array_diff_uassoc
- array_diff_ukey
- array_fill
- array_fill_keys
- array_filter
- array_flip
- array_intersect
- array_intersect_assoc
- array_intersect_key
- array_intersect_uassoc
- array_intersect_ukey
- array_key_exists
- array_key_first
- array_key_last
- array_map
- array_merge
- array_merge_recursive
- array_multisort
- array_pad
- array_pop
- array_product
- array_push
- array_rand
- array_reduce
- array_replace
- array_replace_recursive
- array_reverse
- array_search
- array_shift
- array_slice
- array_splice
- array_sum
- array_udiff
- array_udiff_assoc
- array_udiff_uassoc
- array_uintersect
- array_uintersect_assoc
- array_uintersect_uassoc
- array_unique
- array_unshift
- array_values
- array_walk
- array_walk_recursive
- arsort
- asort
- compact
- count
- current
- end
- extract
- in_array
- key
- key_exists
- krsort
- ksort
- list
- natcasesort
- natsort
- next
- pos
- prev
- range
- reset
- rsort
- shuffle
- sizeof
- sort
- uasort
- uksort
- usort
