Java中的父子参数化构造函数

Question

Normal testing for Parent and child constructors in Java, so I use parameterized constructors in both parent and child class,
But I didn't get the right output.

class A {

    A(int i) {
        System.out.println(i);
    }
}



class B extends A {

    B(int i, int j) {
        System.out.println(i+j);
    }
}



public class Test {

    public static void main(String args[]) {    
        B b = new B(5,7);
    }
}

Answer 1

Class B extends Class A which has a non-empty constructor.
So when we try to construct an instance of Class B , we should call the parent constructor first
By calling super(...) keyword

super(integerValue);