Why default constructor is required in a parent class if it has an argument-ed constructor?

Question

Why default constructor is required(explicitly) in a parent class if it has an argumented constructor

class A {    
  A(int i){    
  }
}

class B extends          


        

Answer 1

Why default constructor is required(explicitly) in a parent class if it has an argumented constructor

I would say this statement is not always correct. As ideally its not required.

The Rule is : If you are explicitly providing an argument-ed constructer, then the default constructor (non-argumented) is not available to the class.

For Example :   
class A {    
  A(int i){    
  }
}

class B extends A {
}

So when you write

B obj_b = new B();

It actually calls the implicit constructor provided by java to B, which again calls the super(), which should be ideally A(). But since you have provided argument-ed constructor to A, the default constructor i:e A() is not available to B().

That's the reason you need A() to be specifically declared for B() to call super().