array_key_exists
Description
The array_key_exists of Array for PHP checks if the given key or index exists in the array.
Syntax
array_key_exists( string|int|float|bool|resource|null $key, array $array ): bool
Parameters
key
Value to check.
array
An array with keys to check.
Return
Returns true on success or false on failure.
Examples
1 · key · null · array
<? $key = null; $array = [ null => 0, null => 1 ]; $return = array_key_exists($key, $array); var_export($return);
true
2 · key · bool · array
<? $key = false; $array = [ false => 0, true => 1 ]; $return = array_key_exists($key, $array); var_export($return);
true
3 · key · int · array
<? $key = 0; $array = [ 0, 1 ]; $return = array_key_exists($key, $array); var_export($return);
true
4 · key · float · array
<? $key = 0.1; $array = [ 0.1 => 0, 0.2 => 1 ]; $return = array_key_exists($key, $array); var_export($return);
true
5 · key · string · array
<? $key = "a"; $array = [ "a" => 0, "b" => 1 ]; $return = array_key_exists($key, $array); var_export($return);
true
6 · key · resource · array
<? $filename = $_SERVER["DOCUMENT_ROOT"] . "/assets/txt/1.txt"; $mode = "r"; $resource = fopen($filename, $mode); $key = get_resource_type($resource); $array = [ "stream" => 0, "stream" => 1 ]; $return = array_key_exists($key, $array); var_export($return);
true
Links
Array
- array
- array_all
- array_any
- 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_find
- array_find_key
- array_flip
- array_intersect
- array_intersect_assoc
- array_intersect_key
- array_intersect_uassoc
- array_intersect_ukey
- array_key_first
- array_key_last
- array_keys
- 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