Implement Polymorphisum using suitable example in Java

Program 1:

public class Username {

public void method(String name, int id) {

System.out.println("Method 1");

}

public void method(int id, String name) {

System.out.println("Method 2");

}

public static void main(String[] args) {

Username obj = new Username();

obj.method(23, "Hello");

obj.method("Hello", 23);

}

}

Program 2:

class MobileOS{

public void display() {

System.out.println("Mobile os");

}

}

class Android extends MobileOS{

public void display() {

System.out.println("Android");

}

}

class iOS extends MobileOS{

public void display() {

System.out.println("iOS");

}

}

public class OS {

public static void main(String[] args) {

Android obj1 = new Android();

iOS obj2 = new iOS();

obj1.display();

obj2.display();

}

}