What is the main purpose of using macros in C?

The main purpose of using macros in C is to replace tokens with specified values. Macros are defined using the #define directive, allowing programmers to create symbolic constants and make code easier to read and maintain. When the preprocessor encounters a macro, it substitutes the defined name with its corresponding value or code fragment throughout the code before compilation. This capability can streamline code by avoiding repetitive typing and reducing potential errors, as you can change the macro definition in one place rather than altering multiple instances throughout the code.

Using macros for this substitution also allows programmers to create inline functions or code snippets that enhance readability. However, this macro replacement occurs at compile time, providing no runtime efficiency advantages, and macros do not inherently manage memory or data types, which distinguishes their purpose from aspects focused on memory optimization or creating complex data types.