array_key_exists
Checks if the given key or index exists in the array
&reftitle.description;
boolarray_key_exists
stringintfloatboolresourcenullkey
arrayarray
array_key_exists returns &true; if the
given key is set in the array.
key can be any value possible
for an array index.
&reftitle.parameters;
key
Value to check.
array
An array with keys to check.
&reftitle.returnvalues;
&return.success;
array_key_exists will search for the keys in the first dimension only.
Nested keys in multidimensional arrays will not be found.
&reftitle.changelog;
&Version;
&Description;
8.5.0
Using null in the key parameter is deprecated, use an empty string instead.
8.0.0
The key parameter now accepts
bool, float, int,
null, resource, and
string as arguments.
8.0.0
Passing an object to the array parameter is no longer supported.
7.4.0
Passing an object to the array parameter has been deprecated. Use property_exists instead.
&reftitle.examples;
<function>array_key_exists</function> example
1, 'second' => 4];
var_dump(array_key_exists('first', $searchArray));
?>
]]>
&example.outputs;
<function>array_key_exists</function> vs <function>isset</function>
isset does not return &true; for array keys
that correspond to a &null; value, while
array_key_exists does.
null, 'second' => 4];
var_dump(isset($searchArray['first']));
var_dump(array_key_exists('first', $searchArray));
?>
]]>
&example.outputs;
&reftitle.seealso;
isset
array_keys
in_array
property_exists