Question

i was developing the below code….

class P {
    //public P(){}
    public P(int i) {

    }
}

class D extends P {
    public D(){ // default constructor must be defined in super class

    }
}

public class agf {      
    public static void main(String[] args) {

    }
}

Now in class p explicit parametrized constructor is defined and in class D default constructor is defined but it is still showing the compile time error ,please explain

Answer 1

In the subclass, if you don’t invoke a superclass constructor explicitly, there must be a default superclass constructor that the VM can invoke for you.

In the superclass, if you explicitly define a constructor, the default no-argument constructor is NOT generated by the compiler.

Therefore, in the situation you show, you defined a non-default constructor in the superclass, which prevented the compiler from generating the default no-arg constructor. Then in the subclass, you didn’t explicitly invoke a constructor in the superclass. The compiler tried to generate a no-arg superclass constructor call and didn’t find a suitable constructor to call.