constructors and destructors in C++

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Classes with applications in C++
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We can use a constructor as a function and can pass arguments to it, but it must have no return type. Destructors are also member function of the class which Performs termination housekeeping before the system reclaims the object’s memory.  It is simply the Complement of the constructor. There can only be one destructor inside a class with no return type and receives no parameters and used with a sign “ ~ ” before its name.
We will get it clear from the below example:

  1. //constructors and destructors in c++ example
  2. //constructors and destructors, constructors with different arguments
  3. #include<iostream>
  4. #include<string>
  5. using namespace std;
  6. class point
  7. {
  8. private:
  9.     int x;
  10.     int y;
  11. public:
  12.     point();
  13.     point(int);
  14.     point(int,int);
  15.     ~point()
  16.     {
  17.     cout<<“THE DESTRUCTOR IS CALLED”<<endl;
  18.     };
  19.     void print();
  20. };
  21.  
  22. point::point()
  23. {
  24.     x= 0;
  25.     y = 0;
  26.     cout<<“no argument “<<“x = “<<x<<” and y = “<<y<<endl;
  27. }
  28.  
  29. point::point(int a)
  30. {
  31.     x = a;
  32.     y = a;
  33.     cout<<“with one argument “<<“x = “<<x<<” and y = “<<y<<endl;
  34. }
  35.  
  36. point::point(int a, int b)
  37. {
  38.     x= a;
  39.     y = b;
  40.     cout<<“with two arguments “<<“x = “<<x<<” and y = “<<y<<endl;
  41. }
  42.  
  43. int main()
  44. {
  45.     point p;
  46.     point p1(1);
  47.     point p2(6,5);
  48.  
  49.     return 0;
  50. }

Now we defined a class point, you can see that we used our constructors and destructors in it, both constructors and destructors are defined in a manner as described before, we described constructors in three different manners, one with no argument, second with one argument and third with two arguments and initialized the values of the private members. Similarly we called a destructor with a “ ~ ” sign before it and its description. In main() we called all our constructors in three different ways. Now after execution all constructors and destructors is automatically called, means that destructor is called three times, So for every constructor there is a destructor, no matter whatever that is. And that’s all about constructors and destructors.

 

Classes with applications in C++
Getting Data from MySql table in php

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