The Anatomy of a C++ Program

Lines beginning with # are Preprocessor Directives — they run before the code compiles.

The most common directive is #include, which inserts the contents of another file at that line.

// Angle brackets = standard library
#include <iostream>

// Quotes = custom/local headers
#include "Editor.h"

Names given to sections of code to avoid naming conflicts.

• Use double colons :: to invoke a namespace inline — e.g. std::cout
• using namespace std; — defines std namespace scope for the entire file
• using std::cout; — more restrictive; only imports that specific name

• Must be declared before they are used in code
• Can be declared and defined in the same place

• cout uses << (insertion operator) for output
• cin uses >> (extraction operator) for input
• cin reads input until it hits a space — so it can't capture a full line on its own

To read an entire line including spaces, use getline():

string fullName;
getline(cin, fullName); // reads until newline, not just first word