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

(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 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 5, PHP 7) Attempt to load undefined class

(PHP 4, PHP 5, PHP 7) Retrieves the parent class name for object or class