what is the use of :: in c++?

[abhinavT]

what is the use of :: in c++?

[bheadmaster]

"::" is the scope resolution operator, and it is used to define scope of namespaces and classes, outside of them.

For example, when we want to implement a class method outside of the class definition:

class MyClass {
  public:
    void SomeMethod();
};

void MyClass::SomeMethod() {
    // do something...
}

Or when we want to access static members of a class from outside:

class MyClass {
  public:
    static void StaticMethod() {
        // do something...
    }
}

int main()
{
    MyClass::StaticMethod(); // call the static function from MyClass...
}

Or when we want to use objects defined in the "std" namespace:

#include <iostream>

int main()
{
    std::cout << "We used an object from 'std' namespace" << std::endl;

    return 0;
}