How do I use directives in C++?

How do I use directives in C++?

In C++, directives are used to give instructions to the compiler. The most common ones are preprocessor directives like #include and #define.

Can you explain what #include does?

Sure! The #include directive is used to include the contents of a file, typically a header file, into your program. This allows you to use functions and classes defined in that file.

What about #define? How is it used?

The #define directive is used to create macros. It allows you to define a constant or a function-like macro that can be used throughout your code.

Are there any best practices for using directives?

Yes, it's best to include only the necessary headers, avoid using #define for constants in favor of const or constexpr, and use include guards to prevent multiple inclusions.