(PHP 5, PHP 7) Checks if user defined public

(PHP 5 >= 5.1.0, PHP 7) Checks if constant is defined

(PHP 5 >= 5.2.0, PHP 7) Gets external variables and optionally filters them

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Check for alphanumeric character(s)

(PHP 5 >= 5.2.3, PHP 7) Gets parameter position

(PHP 4, PHP 5, PHP 7) Sort an array by key in reverse order

(PHP >= 5.4.0) Returns an array of trait aliases

(PHP 7) Gets the executing

(PHP 5, PHP 7) Checks if user defined public

(PECL quickhash >= Unknown) This method deletes am entry from the hash