👉 The `#include` directive in C++ is used to include the contents of another file into the current file, allowing you to reuse code, definitions, and functions defined elsewhere. This mechanism promotes modularity and code reusability by enabling developers to integrate functionalities from multiple sources into a single project without duplicating code. For example, if you have a header file `math_utils.h` containing mathematical functions, you can include it in another source file to use those functions directly. This not only simplifies maintenance but also enhances the organization and scalability of your codebase.
