Question

Can you tell me the difference between a . and -> call to a method in C++.

This code works fine, using both calling methods.

#include <iostream>

using namespace std;

class myclass
{
    public:
    string doSomething();
};


string myclass::doSomething()
{
    return "done something\n";
}

int main (int argc, const char * argv[])
{
    myclass c;
    std::cout << c.doSomething();

    myclass *c2;    
    std::cout << c2->doSomething();

    return 0;
}

I don’t understand the different between the 2 calls? they both work?

Answer 1

The arrow operator is meant for calling a method from a pointer to an instance of an object.

The dot operator is meant for calling a method from a reference to an instance of an object, or on a locally defined object.

Your code would not compile if you reversed the operators on the two examples.