(PHP 5 >= 5.4.0, PHP 7) Checks if the trait exists

(PHP 4, PHP 5, PHP 7) Get the default properties of the class

(PHP 4, PHP 5, PHP 7) Gets the class methods' names

(PHP 4, PHP 5, PHP 7) Checks if the class has been defined

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Checks if the object is of this class or has this class as one of its parents

(PHP 4, PHP 5, PHP 7) Returns an array with the name of the defined classes

(PHP 5 >= 5.3.0, PHP 7) the "Late Static Binding" class name

(PHP 4, PHP 5) Call a user method on an specific object

(PHP 4 >= 4.0.5, PHP 5) Call a user method given with an array of parameters

(PHP 5, PHP 7) Attempt to load undefined class