Why do I need to write a constructor here explicitly?

Question

This is how I encountered the problem. I am giving an example:

package check;

public class Check {
  int a,b;
  Check (int i,int j) {
    a = i;
    b = j;
         


        

Answer 1

Why is it compulsory to use a constructor at all for class V?

It is because In the check class you are explicitly use an parametrized constructor and is also the super class of class V, So if you are not mentioning paramaterized constructor then you need to call super() explicitly and again if you are not defining any parametized constructor in check class then compiler is going to invoke an default no-argument constructor and there it will place super() which is responsible to call Object class constructor .