method overloading in C++

```
#include <iostream>
using namespace std;

class Addition
{
    public:
    int sum(int a,int b) 
    {
        return a+b;
    }
    int sum(int a,int b, int c) 
    {
       return a+b+c;
    }
};
 
int main(void)
{
    Addition obj;
    cout<<obj.sum(20, 15)<<endl;
    cout<<obj.sum(81, 100, 10);
    return 0;
}
```