DESTRUCTORS

A destructor is also a member function that is automatically invoked. It is also a special member function like constructor.

Constructor constructs the object, whereas the destructor destroys the object.

A destructor deallocates the memory dynamically allocated to the variable(s) or performs other clean up operations.

• The name of the destructor is also the same as the class name.
• The destructor’s name is preceded by the tilde symbol „~‟.
• A destructor is called when an object goes out of scope.
• A destructor is also declared in the public section.
• Destructors do not take any argument and hence cannot be overloaded.
• A destructor does not return any value.
• A destructor is defined to free (de-allocate) the resources allocated in the program.
• The address of a destructor cannot be accessed in the program.
• Constructors and destructors cannot be inherited.
• A class can have only one destructor.
• Like constructor, a destructor is also invoked once for each object.

Syntax:-

public:

~classname()

{

-----

}

Example. //demonstrating constructor and destructor

#include<iostream.h>

class sample

{

private:

int x;

public:

sample (int a)

{

x=a;

cout<<"Constructor called for object with value : "<<x<<endl;

}

~sample()

{

cout<<"Destructor called for object with value : "<<x<<endl;

}

};

void main()

{

clrscr();

sample s1(1);

sample s2(2);

sample s3(3);

}

Output:

Constructor called for object with value : 1

Constructor called for object with value : 2

Constructor called for object with value : 3

Destructor called for object with value : 3

Destructor called for object with value : 2

Destructor called for object with value : 1