#include<iostream>
using namespace std;

class Addition
{
int a, b;
public:
//here Parameterize constructor created
Addition(int, int);
//here destructor create, it is automatically called when constructor called.
~Addition();
int add()
{
return(a + b);
}
};
Addition::Addition (int x, int y)
{
a = x;
b = y;
};
Addition::~Addition ()
{
cout << "memory deallocation\n";
}
int main ()
{
//the constructor that have argument, is called parameterize constructor
Addition obj (3, 4);
cout << "sum " <<obj.add()<<"\n";
return 0;
}
Output:- sum 7
memory deallocation
 
Example of default constructor
#include<iostream>
using namespace std;

class Subtraction{
   public:
    int a,b;
    int sub(int a,int b){
        return(a-b);
    }
//create default constructor
    Subtraction();   
};
//access the default constructor by using scope resolution
Subtraction::Subtraction(){
   
}
int main(){
    Subtraction subtr;
    cout<<"subtraction: "<<subtr.sub(5,9);
}