# Managing inheritance

A subclass is a class that inherits properties and methods from another class, called the superclass. The `extends` clause of the class statement lets you specify a class's superclass.

    class subClass extends superClass {
    	// Class properties, methods.
    }

The subclass inherits all the properties and methods of the superclass, including private properties and methods (see "Static, public, and private members" on page 140). A class can only inherit from a single class. A subclass can only inherit from a single superclass. Multiple inheritance is not allowed.

Classes you create can extend any of the built-in ActionScript classes like MovieClip, Button, or XML.