A constructor in C++ is a special member function that is called automatically when an object of a class is created. It has the same name as the class and does not have a return type. The purpose of a constructor is to initialize the data members of the object.

Here are some key points about constructors in C++:

• A constructor is a special type of member function that is used to initialize the data members for an object of a class automatically when an object of the same class is created.
• Constructors can be defined inside or outside the class.
• Constructors can take parameters, just like regular functions.
• Constructors can be overloaded, meaning that a class can have multiple constructors with different parameter lists.
• If a class does not have a constructor defined, the compiler will provide a default constructor with an empty code and no parameters.

In summary, a constructor is a special member function that is used to initialize the data members of an object when it is created. It has the same name as the class and does not have a return type. Constructors can be defined inside or outside the class, can take parameters, and can be overloaded.