Is Constructor Overriding Possible?

Question

What i know is, the compiler writes a default no argument constructor in the byte code. But if we write it ourselves, that constructor is called automatically. Is this phenomena a constructor overriding?

Answer 1

Constructors are not normal methods and they cannot be "overridden". Saying that a constructor can be overridden would imply that a superclass constructor would be visible and could be called to create an instance of a subclass. This isn't true... a subclass doesn't have any constructors by default (except a no-arg constructor if the class it extends has one). It has to explicitly declare any other constructors, and those constructors belong to it and not to its superclass, even if they take the same parameters that the superclass constructors take.

The stuff you mention about default no arg constructors is just an aspect of how constructors work and has nothing to do with overriding.

Answer 2

What you describe isn't overriding. If you don't specify a default constructor, the compiler will create a default constructor. If it's a subclass, it will call the default parent constructor(super()), it will also initialize all instance variables to a default value determined by the type's default value(0 for numeric types, false for booleans, or null for objects).

Overriding happens when a subclass has the same name, number/type of parameters, and the same return type as an instance method of the superclass. In this case, the subclass will override the superclass's method. Information on overriding here.