When the constructor taking no argument is known as 0-arg constructor. Let’s see an example for better clarity.

ConstructoeExample1.java

class A
{
    int x,y;
    A()      //0-arg constructor
    {
  		x=100;
  	  y=200;
    }
    void show()
    {
  		System.out.println("x="+x);
  		System.out.println("y="+y);
    }
}
class ConstructorExample1
{
    public static void main(String[] args)
    {
  		  A obj=new A();
  		  obj.show();
    }
}

Output: