Chapter 9.3, Problem 15SC

Program Plan Intro

Method Overriding:

• Overriding is a feature that allows a child class or subclass to specifically implement a method that already provided by one of its parent classes or super classes.
• If the method of the subclass has name, parameters and return type as same as the method in the super class, then the method in the subclass is said to override the method in the super-class.

“super” keyword:

• The keyword “this” is a reference variable that used to refer to the parent class objects.
• The “super” keyword is used in the following contexts:
  • Use of keyword “super” with variables:
    • This situation comes when the base class and derived class has the same data members.
    • In this situation, ambiguity occurs for the Java Virtual Machine.
    • For avoiding ambiguity, the keyword “super” is used as reference to the variables of super class.
  • Use of keyword “super” with methods:
    • The keyword “super” is used to call methods of base class.
    • When the base class and derived class has same methods, the keyword “super” is used to refer to the methods of base class. Through this ambiguity is resolved.
  • Use of keyword “super” with constructors:
    • The keyword “super” can be used to access the constructors of base class.