ObjectMethods.java

package JavaLangPackage;

// This class inherited from Object Class
class MyObject extends Object{
    @Override
    public String toString(){
        return "Overwritten toString";
    }
    @Override
    public int hashCode(){
        return 999;
    }
    public boolean equals(MyObject O){
        return this.hashCode()==O.hashCode();
        // return true if the object which called this equals() have hashCode as O hashCode.
    }
}

public class ObjectMethods {
    public static void main(String[] args) {
        MyObject O1 = new MyObject(); // first Object created and O1 holding that object
        System.out.println(O1); // Will call toString() by default
        System.out.println(O1.toString());
        System.out.println(O1.hashCode()); // Unique ID generated by JVM using Address

        MyObject O2 = new MyObject(); // second Object created O2 holding that object
        System.out.println(O2);
        System.out.println(O2.hashCode());
        System.out.println(O1.equals(O2)); // return whether they are pointing same object or not
        O1 = O2;  // O1 reference updated with O2 reference
        System.out.println(O1.equals(O2));
        System.out.println(O1.hashCode()); // Both will have same hashcode
        System.out.println(O2.hashCode());
    }
}