Use of super keyword in Java

The super keyword is another important one. This is a reference variable that is used to call the immediate parent class. This keyword is expensive when we talk about Inheritance and Polymorphism. There are three uses of the super keyword. 

1. super with variables
2. super with constructors
3. super with method overriding 

Super with variables

• If you use super with instance variables, it will refer to the variables of the immediate parent class.
• Look at the following example.

Super with constructors

• We can use the super keyword to invoke the constructor of the immediate parent class 
• Once you instantiate a class, the compiler calls the default constructor of that class.

Super with method overriding

• If you want to call methods in the parent class, you can use super keyword.
• In overriding, it will call the child class method instead of the parent class.
• Look at the following example.