Types Of Constructor In C++ | Types Of Constructor In C++ With Example | Types Of Constructor In C++ With Program | Types Of Constructor In C++ In Hindi

Types Of Constructor In C++

• Default constructor
• Parameterized constructor
• Copy constructor

Fig:Types Of Constructor In C++ 

1.   Default Constructor

 

A constructor that doesn’t have parameters. It is invoked automatically and can carry default values. If we do not define constructor it will still define an empty constructor.

Synatx:

class BCA

{

int a,b;

public:

class name()//default constructor

{

---

---

}

};

Program:

#include<iostream.h>

#include<conio.h>

class BCA

{

private:

int a,b;

public:

BCA()

{

cout<<”default constructor create”;

}

void display()

{

cin>>a>>b;

cout<<”a=”<<a;

cout<<”b=”<<b;

}

};

void main()

{

BCA a1;

a1.display();

getch();

}

Output:

Default constructor create a=0 b=775

    

    2.   Parameterize Constructor

When we can pass values to constructor it is called parameterized constructor. Passing values to the constructors are same as with functions. It is used to initialize variables in a class.

Synatx:

class BCA

{

int a,b;

public:

class name(argument)//parameterize constructor

{

---

---

}

};

Program:

#include<iostream.h>

#include<conio.h>

class BCA

{

private:

int a,b;

public:

BCA(int x, int y)

{

cout<<”parameterize constructor create”;

a=x;

b=y;

}

void display()

};

void BCA::display()

{

cout<<”a=”<<a;

cout<<”b=”<<b;

}

void main()

{

BCA a1(100,200);

a1.display();

getch();

}

Output:

Parameterize constructor create a=100 b=200    

      

     3.   Copy Constructor

A copy constructor is used to copy the variable of one object into another object.

Synatx:

class BCA

{

int a,b;

public:

class name(class name &object name)//copy constructor

{

---

---

}

};

Program:

#include<iostream.h>

#include<conio.h>

class BCA

{

private:

int a,b;

public:

BCA()//default constructor

{

cout<<”create a constructor”;

a=0;

b=0;

}

BCA(int x, int y)//parameterize constructor

{

a=x;

b=y;

}

BCA(BCA &p)//copy constructor

{

a=p.a;

b=p.b;

}

void display()

{

cout<<a;

cout<<b;

}

};

void main()

{

BCA a1;

BCA a2(10,20);

BCA a3(a2);

a1.display();

a2.display();

a3.display();

getch();

}

Output:

Create constructor 0010201020