These reference sections make easy quick references in the future when you find you need to solve a particular programming problem.
C Standard Libraries: A collection of useful data manipulation and system functions.
Command-Line Processing: Ways to receive information from the users when a program runs.
Preprocessor Directives: Useful macros and techniques for making programming more flexible and making programs easier to maintain.
C++ Standard Libraries: Similar to the C standard libraries, with some useful extensions.