Constructor and Destructor of a class in C++ Exercise with Examples

What is a constructor in C++?

The constructor is a member function of the class. The constructor has the same name as the name of its class.

When a new object of the class is executed, the constructor also executed automatically.
The constructor has no data type. Constructors can’t return any value. Even we can’t use void for the constructor.
The constructor can have arguments.
The constructor can be only public.
There is no inheritance of the constructor.
Constructors can’t be virtual.
The Constructor can’t be referred by its address.

What is the purpose of the constructor of a class?

The main purpose of the constructor is to assign initial values to the elements of the class.

Program of the constructor of a class

#include<iostream> 
using namespace std;
class t4tutorials
{
public:
t4tutorials() {
cout<<"welcome to T4Tutorials.com"<<endl;
}
};
int main(){
t4tutorials x, y, z;
}

Output

welcome to T4Tutorials.com

#include<iostream> 
using namespace std;
class t4tutorials
{
public:
t4tutorials() {
cout<<"welcome to T4Tutorials.com"<<endl;
}
};
int main(){
t4tutorials x, y, z, j;
}

Output

Welcome to T4Tutorials.com

Difference Between Constructor VS Destructor

Purpose of Constructor and destructor

CONSTRUCTOR: The constructor allocates the memory to an object.

DESTRUCTOR: Destructor de-allocates the memory of an object.

Declaration of Constructor and destructor

CONSTRUCTOR: name_of_class( arguments of constructor ){ };

DESTRUCTOR: ~ name_of_class(){ };

Note: No arguments of destructor

Arguments of Constructor and destructor

CONSTRUCTOR: Constructor accepts arguments.

DESTRUCTOR: Destructor does not accept any argument.

How to call Constructor and destructor

CONSTRUCTOR: Constructor is called automatically when the object is created.

DESTRUCTOR: Destructor is called automatically, as the block is exited or when the program terminates.

Working of Constructor and destructor

CONSTRUCTOR: Constructor allows the objects of the class to initialize some of the constructor values before, it is used.

DESTRUCTOR: Destructor allows an object of the class to destroy the values of the constructor when destructor is called.

Order of execution of Constructor and destructor

CONSTRUCTOR: Constructor are called in successive order.

DESTRUCTOR: Destructor are called in reverse order of constructor.

How many Constructor and destructors are possible in a program?

CONSTRUCTOR: There can be multiple constructors of a single class, and this concept is known as constructor overloading.

DESTRUCTOR: There is always only a single destructor for one class.

Copy Constructor

CONSTRUCTOR: Copy constructor allows a constructor to declare and initialize an object from another object.

DESTRUCTOR: There is no such concept as copy constructor.

Overloading of Constructor and destructor

CONSTRUCTOR: Constructors can be overloaded

DESTRUCTOR: Destructor can’t be overloaded.

Constructor Destructor C++ Exercise with Solution

Write a program in C++ to convert a decimal number into binary without using an array and using the constructor and destructor. – Solution
Write a program in C++ to convert a decimal number into binary without using an array by using the constructor overloading. – Solution
Write a c++ program to find out the sum of an A.P. series using constructor and destructor. – Solution
Write a c++ program to find out the sum of an A.P. series by using the constructor overloading. – Solution
Write a program in C++ to print Floyd’s Triangle by using the constructor destructor. – Solution
Write C++ Program to display the cube of the number up to a given integer using Destructor. – Solution
Write C++ Program to display the cube of the number up to a given integer using constructor overloading. – Solution
Write a C++ program to find Strong Numbers within a range of numbers using constructor C++. – Solution
Write a C++ program to find Strong Numbers within a range of numbers Using destructor in C++. – Solution
Write a C++ program to find Strong Numbers within a range of numbers by using constructor overloading in C++. – Solution
Let’s see the C++ program to show the Sum of n number of odd natural numbers by using the Constructor Overloading. – Solution
Let’s see the Sum of n number of an odd natural number using constructor and destructor in C++. Solution
Sum of the series Using Constructor Overloading in C++. Solution
Sum of the series Using Destructor in C++. Solution
Sum of the series Using Constructor in C++. Solution
Write a program in C++ to find the sum of the series using the constructor overloading. Solution
Write a program in C++ to find the sum of the series by using the constructor and destructor. Solution
Write a program in C++ to print a pattern of right angle triangle with a number that will repeat a number in the row by using the constructor and destructor. Solution
Write a program in C++ to print a pattern of right angle triangle with a number that will repeat a number in the row by using the constructor overloading. Solution
Write a C++ program to display Pascal’s triangle using the Constructor Destructor. Solution
Write a C++ program to display Pascal’s triangle using the Constructor Overloading. Solution
C++ program of Constructor Destructor to display a pattern for a number of rows. Solution
C++ program Constructor Destructor program to print the hollow square or rectangle star pattern. Solution.
C++ program to display the diamond-like pattern using the Constructor Destructor. Solution
C++ program to display the diamond-like pattern using the Constructor Overloading. Solution
Write a program in C++ to convert an octal number into binary using constructor and destructor. Solution
Write a program in C++ to convert an octal number into binary using constructor overloading. Solution
C++ Program with constructor destructor to display the pattern like pyramid. Solution
Write a C++ Program to display the reverse of a number using the constructor destructor. Solution
Write a C++ Program to display the reverse of a number using the constructor overloading. Solution
Write a C++ program to print rhombus star pattern of Number of rows using constructor overloading and destructor. Solution
Write a program in C++ to Check Whether a Number can be Express as Sum of Two Prime Numbers using constructor and destructor. Solution
Write a program in C++ to find the sum of the series using constructor destructor. Solution
Write a C++ program of binary to octal conversion with Constructor with constructor. Solution
Write the Octal to Decimal number program in C++ using constructor overloading and destructor? Solution
Write a program in C++ to make such a pattern like a pyramid with a number which will repeat the number in the same row using constructor overloading and destructor. Solution
Write a C++ program to find the number and sum of all integer between 100 and 200 which are divisible by 9 with constructor destructor. Solution
Constructor Fibonacci series C++ Program. Solution

Test Your Understandings

1.Multiple constructor for a class are possible? YES / NO

Answer - Click Here:

Yes

2. Contructor for a class is represented with tild sign ∼?

Answer - Click Here:

3. Constructor overloading is very helpful to free the computer memory?

Answer - Click Here:

Topic Covered

Constructor of a class, Purpose of Constructor in C++ OOP.