Why i have to create 2 myclass constructors to use the operator overloading?

Question

class MyClass {
public:
int var;
MyClass(){};
MyClass(int a)
: var(a) { }

MyClass operator+(MyClass &obj) {
MyClass res;
res.var= this->var+obj.var;
return res;
}
};

int main() {
MyClass obj1(12), obj2(55);
MyClass res = obj1+obj2;

cout << res.var;

Answer 1

You don't. The code would work as coded without the first one. This is how to code it without the second.
https://code.sololearn.com/c4y5VWVOSofP