_______ is used to declare and initialize an object from another object of same class in C++.

Question

Accepted Answer

The correct option is (1):
A **Copy constructor** is a special member function in C++ explicitly designed for object initialization scenarios where a new object is created as a copy of an existing object of the same class. Its primary role is to ensure that when you declare a new object and initialize it with an old one (e.g., MyClass obj2 = obj1; or MyClass obj2(obj1);), the new object receives a correct, member-by-member duplicate of the source object's data. This process is fundamental to preventing issues like shallow copying of pointers, which could lead to multiple objects sharing the same dynamic memory. The copy constructor's signature typically takes a reference to the class type itself (e.g., ClassName(const ClassName& other)) to perform the necessary object-to-object initialization.

The incorrect option is (2):
The **Default constructor** is used for initializing an object when no arguments are provided during its creation (e.g., MyClass obj;). Its purpose is to provide a default starting state for a new object, not to perform a copy operation from another fully formed object. The compiler automatically provides one if no user-defined constructors exist, but it is defined to take zero parameters. Therefore, it cannot accept an existing object as an initializer to facilitate a copy.

The incorrect option is (3):
**Overloaded constructor** is a general term that refers to a class having multiple constructors with different parameter lists. While a copy constructor is technically a form of overloading because it is distinct from the default or parameterized constructors, this option is too broad and does not specifically name the unique mechanism for initialization *from another object*. An overloaded constructor could simply be any parameterized constructor, which takes arbitrary arguments to set an object's state, but not necessarily to duplicate another object.

The incorrect option is (4):
A **Non-parametrized constructor** is simply another name for a default constructor that takes no arguments. Like the default constructor, its function is to create a new object from scratch without any external data passed during the initialization call. Since it is strictly defined as a constructor that accepts zero parameters, it logically cannot accept an existing object reference as an argument, which is the required signature for copying an object.