What is Constructor Types of Constructor precat

 

What is Constructor? and what type ?

  Constructor

• It is a member function of a class used to initialize object. 
• Constructors get automatically called when the object is created i.e. memory is allocated to object. 

•  If we don’t write any constructor, the compiler provides a default constructor. 

•  Constructor has the same name as that of class and doesn’t have any return type. 

• 
  

 Due to following reasons, the constructor is considered a special function of the class: 

1. Its name is same as class name. 

2. It doesn't have any return type. 

3. It is designed to call implicitly.

 4. In the life time of the object , it gets called only once per object and according to order of its declaration.

•  We can not call the constructor on an object, pointer or reference explicitly. It is designed to call implicitly. 

• We can not declare the constructor static, constant, volatile or virtual. We can declare constructor only inline. 

• Constructor overloading means inside a class more than one constructor is defined.

•  We can have constructors with 

•  No argument: 
• initialise data member to default values 

• One or more arguments: 
• initialize data member to values passed to it 

 The argument of type of object : 

                initialize the object by using the values of the data members of the passed object. It is called a copy constructor.

Types of Constructor

Parameterless constructor

                    • also called zero argument constructor or user defined default constructor

            • If we create object without passing argument then parameterless constructor gets called

            • Constructor do not take any parameter

Parameterized constructor

• If constructor take parameter then it is called parameterized constructor

• If we create object, bypassing the argument then paramterized constructor gets called

Default constructor

• If we do not define constructor inside class then compiler generates default constructor for the class.

• Compiler generated default constructor is parameterless.

Copy constructor

Copy constructor is a single parameter constructor hence it is considered a parameterized constructor