What and how is this legal problem in java inheritence?

Question

The following program leads to an error message of the type "constructor A () not found in class A":

class A {
   A (int i) {}
} 
class B extends A {}

If a constructor as defined below is in class B, however propose a legal program. Why?

class B extends A {
  B (int i) {
      super (i);
  }
}

score 0 · Answer 1 · answered Nov 03 '20 at 05:19

0

If you don't define a constructor, you get a default 0-ary constructor which does nothing except call the super constructor. So your first B class looks like

class B extends A {
  B() {
    super();
  }
}

And there's no A() for the super call to resolve to, hence the error. For this reason, the only time you can omit a constructor in a child class is if the parent can be default constructed.

answered Nov 03 '20 at 05:19

Silvio Mayolo

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I didn't find any error when I Did the same in my compiler. – Vyom Yadav Nov 03 '20 at 05:25
super calls the constructor of the parent class with the same signature right? So I couldn't get whats the problem here. – Vyom Yadav Nov 03 '20 at 05:27
is the Error because he defined some object like `A obj = new A();` – Vyom Yadav Nov 03 '20 at 05:30

What and how is this legal problem in java inheritence?

1 Answers1