What is overriding and overloading under polymorphism in java?

Overriding − If super class and subclass have methods with same name including parameters. JVM calls the respective method based on the object used to call the method.

i.e. if the current object using which the method is called, is of super class type the method of the super class is executed.

Or, if the object is of the type subclass then the method of the super class is executed.

Example

Live Demo

class SuperClass{
   public static void sample(){
      System.out.println("Method of the super class");
   }
}
public class RuntimePolymorphism extends SuperClass {
   public static void sample(){
      System.out.println("Method of the sub class");
   }
   public static void main(String args[]){
      SuperClass obj1 = new RuntimePolymorphism();
      RuntimePolymorphism obj2 = new RuntimePolymorphism();
      
      obj1.sample();
      obj2.sample();
   }
}

Output

Method of the super class
Method of the sub class

Overloading − If a class have two or more methods with the same name and different parameters. JVM calls the respective method based on the parameters passed to it, at the time of method call.

Example

Live Demo

public class OverloadingExample {
   public void display(){
      System.out.println("Display method");
   }
   public void display(int a){
      System.out.println("Display method "+a);
   }
   public static void main(String args[]){
      OverloadingExample obj = new OverloadingExample();
      obj.display();
      obj.display(20);
   }
}

Output

Display method
Display method 20