What are C++ preprocessor directives and how do I use them?

What are C++ preprocessor directives and how do I use them?

C++ preprocessor directives are commands that are processed before the actual compilation of the code. They begin with a '#' symbol and are used for various purposes like including files, defining macros, and conditional compilation.

Can you give me an example of a preprocessor directive?

Sure! A common example is #include <iostream>, which includes the standard input-output stream library in your program.

What is the purpose of #define?

The #define directive is used to create macros, which are essentially constants or expressions that can be reused throughout your code.

How does conditional compilation work?

Conditional compilation uses directives like #ifdef, #ifndef, and #endif to include or exclude parts of the code based on certain conditions, allowing for more flexible code management.