super to Access Superclass Members

In Java, the super keyword refers to the immediate parent class of a given object. It is used to access members (fields, methods, and constructors) of the parent class from the child class.

Key Uses of super:

  1. Accessing Superclass Methods: It is used to call a method of the superclass when the subclass has overridden that method.
  2. Accessing Superclass Constructor: It is used to call the constructor of the superclass from the subclass.
  3. Accessing Superclass Fields: It allows access to the fields of the superclass.

Example 1: Using super to call a superclass method

class Animal {
    void eat() {
        System.out.println("Animal is eating...");
    }
}

class Dog extends Animal {
    void eat() {
        super.eat();  // Call the eat() method of the parent class Animal
        System.out.println("Dog is eating...");
    }
}

public class Main {
    public static void main(String[] args) {
        Dog dog = new Dog();
        dog.eat();  // Output will be: Animal is eating... Dog is eating...
    }
}

Example 2: Using super to call a superclass constructor

class Animal {
    Animal() {
        System.out.println("Animal constructor");
    }
}

class Dog extends Animal {
    Dog() {
        super();  // Call the constructor of the parent class Animal
        System.out.println("Dog constructor");
    }
}

public class Main {
    public static void main(String[] args) {
        Dog dog = new Dog();  // Output will be: Animal constructor Dog constructor
    }
}

Example 3: Using super to access a superclass field

class Animal {
    String name = "Animal";
}

class Dog extends Animal {
    String name = "Dog";

    void display() {
        System.out.println("Name from Dog class: " + name);
        System.out.println("Name from Animal class: " + super.name);  // Access the name from Animal class
    }
}

public class Main {
    public static void main(String[] args) {
        Dog dog = new Dog();
        dog.display();  // Output will be: Name from Dog class: Dog Name from Animal class: Animal
    }
}

🔗 Related Notes