Passing parameters to super class constructor in Java

The compiler automatically provides a public no-argument constructor for any class without constructors . This is called the default constructor. If we do explicitly declare a constructor of any form, then this automatic insertion by the compiler won’t occur.

If the parent has no constructor (Object does have one), the compiler will reject the program . But then, Object is a (direct or indirect) superclass of every class in Java. Suppose, we have a class A , which does not extend any class explicitly, so it implicitly extends Object .

Before you can initialize an object in a constructor, the object’s parent constructor must be called first. … The compiler automatically inserts superclass constructor calls in both constructors .