Destructor in C++ | Rules of destructor | Example | My CS Tutorial

Destructor in c++ | Destructor rules | Destructor example | Simple C++ program of destructor | Destructor in c++ programming | My CS Tutorial

Destructor in c++ | My CS Tutorial

A destructor is a special member function that works just opposite to constructor, unlike constructors that are used for initializing an object, destructors destroy (or delete) the object.

C++ Destructor

A destructor is a special member function of a class that is executed whenever an object of it's class goes out of scope or whenever the delete expression is applied to a pointer to the object of that class.

What is C++ destructor ? and when is destructor called?

Destructor is a member function which destructs or deletes an object.
A destructor function is called automatically when the object goes out of scope:
(1) the function ends
(2) the program ends
(3) a block containing local variables ends
(4) a delete operator is called

A destructor will have exact same name as the class prefixed with a tilde (~) and it can neither return a value nor can it take any parameters. Destructor can be very useful for releasing resources before coming out of the program like closing files, releasing memories etc.

Syntax of Destructor

~class_name()  
{
   //Some code
}

Similar to constructor, the destructor name should exactly match with the class name. A destructor declaration should always begin with the tilde(~) symbol as shown in the syntax above.

When does the destructor get called?

A destructor is automatically called when:
1) The program finished execution.
2) When a scope (the { } parenthesis) containing local variable ends.
3) When you call the delete operator.

Destructor Example

#include <iostream>
using namespace std;
class HelloWorld{
public:
  //Constructor
  HelloWorld(){
    cout<<"Constructor is called"<<endl;
  }
  //Destructor
  ~HelloWorld(){
    cout<<"Destructor is called"<<endl;
   }
   //Member function
   void display(){
     cout<<"Hello World!"<<endl;
   }
};
int main(){
   //Object created
   HelloWorld obj;
   //Member function called
   obj.display();
   return 0;
}

Output:

Constructor is called
Hello World!
Destructor is called

Destructor rules

1) Name should begin with tilde sign(~) and must match class name.
2) There cannot be more than one destructor in a class.
3) Unlike constructors that can have parameters, destructors do not allow any parameter.
4) They do not have any return type, just like constructors.
5) When you do not specify any destructor in a class, compiler generates a default destructor and inserts it into your code.


Destructor in c++ | Destructor rules | Destructor example | Simple C++ program of destructor | Destructor in c++ programming | My CS Tutorial

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Created by-- HARSH CHAUHAN