Learning Pre-operations

In C++, the lines of code that start with a pound sign (#) are dedicated commands for the pre-processor, which is basically the part of the compiler that dictates what the compiler is going to need to know. In this screenshot, the user has added the command #include <iostream>, which basically tells the compiler to begin running. The user has also defined variables A and B which are set to 0. And lastly, using namespace std; tells the compiler that each time it sees a command such as cout, (nromally std::cout), it tells it that there is the std:: operator in front of it.