When should I make explicit use of the `this` pointer?

Question

When should I explicitly write this->member in a method of a class?

Answer 1

If you declare a local variable in a method with the same name as an existing member, you will have to use this->var to access the class member instead of the local variable.

#include 
using namespace std;
class A
{
    public:
        int a;

        void f() {
            a = 4;
            int a = 5;
            cout << a << endl;
            cout << this->a << endl;
        }
};

int main()
{
    A a;
    a.f();
}

prints:

5
4