array_key_exists
Checks if the given key or index exists in the array
&reftitle.description;
boolarray_key_exists
mixedkey
arraysearch
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.
search
An array with keys to check.
&reftitle.returnvalues;
&return.success;
&reftitle.changelog;
&Version;
&Description;
5.3.0
This function doesn't work with objects anymore,
property_exists should be used in this case.
&reftitle.examples;
<function>array_key_exists</function> example
1, 'second' => 4);
if (array_key_exists('first', $search_array)) {
echo "The 'first' element is in the array";
}
?>
]]>
<function>array_key_exists</function> vs <function>isset</function>
isset does not return &true; for array keys
that correspond to a &null; value, while
array_key_exists does.
null, 'second' => 4);
// returns false
isset($search_array['first']);
// returns true
array_key_exists('first', $search_array);
?>
]]>
&reftitle.notes;
&info.deprecated.alias;
key_exists
&reftitle.seealso;
isset
array_keys
in_array
property_exists