Abstract methods

Abstract methods are used when you wish to force the developer of a sub-class to override the method and provide functionality.

Methods are declared as abstract by using the abstract keyword, for example

public abstract void abstractMethod { } No code or declarations are allowed inside an abstract method.

It is not possible to declare a method as abstract unless the class is also declared as abstract. See abstract classes.

If a sub-class is created which does not override the abstract methods in its parent, then a compile error will occur where that sub-class is used.