PHP Manual: Splits a key in string representation into array representation

arrayfalse dba_key_split(stringfalsenull $key)

dba_key_split splits a key (string representation) into an array representation.

Returns an array of the form array(0 => group, 1 => value_name). This function will return false if key is null or false.

Version	Description
8.4.0	Passing `null` or `false` to `key` is now deprecated.

dba_key_split