Overriding and Hiding

Overloading
More than one methods have the same name but different signatures

Overriding
Replacing the implementation of a methods in the superclass with one of your own.

• You can only override a method with the same signature.
• You can only override non-static methods.

Hiding
Fields and static methods can not be overridden. They can
only be hidden.

• Hidden fields and static methods are still accessible via references to the superclass.
• A static method can be only be hidden by another static method.
• A static variable may be hidden by an instance variable.

Which implementation is used?

• When invoking a non-static method, the actual class of the object determines. (run-time)
• When accessing a field, the declared type determines. (compile time)
• When invoking a static method, the declared type determines. (compile time)