How do we define a constructor?

A constructor in C++ is a special method that is automatically called when an object of a class is created .

In C++, constructor is a special method which is invoked automatically at the time of object creation. It is used to initialize the data members of new object generally . The constructor in C++ has the same name as class or structure.

In class-based object-oriented programming, a constructor (abbreviation: ctor) is a special type of subroutine called to create an object . It prepares the new object for use, often accepting arguments that the constructor uses to set required member variables.