array_key_exists returns true if the given key is set in the array. key can be any value possible for an array index.
Value to check.
An array with keys to check.
Returns true on success or false on failure.
array_key_exists will search for the keys in the first dimension only. Nested keys in multidimensional arrays will not be found.
For backward compatibility reasons, array_key_exists will also return true if key is a property defined within an object given as array. This behaviour is deprecated as of PHP 7.4.0, and removed as of PHP 8.0.0.
To check whether a property exists in an object, property_exists should be used.