Why Java doesn't provide default constructor, if class has parametrized constructor? [duplicate]

Question

Why Java doesn't provide default constructor, if class has parametrized constructor? Consider the following example

class A {
    int a;

    public A() {
    }

    public A(int val) {
        a = val;
    }
}

Here I explicitly need to add default constructor. Is there any reason, why Java doesn't provide default constructor for class having parametrized constructor?

Answer 1

The reason has to do with a combination of security and interface. The compiler shouldn't give you methods you don't explicitly define. The one exception is a convenience no-arg constructor if you don't specify any constructors. If you do specify a constructor the compiler assumes you don't want any others.