Preprocessor Macros
Preprocessor macros are a feature in programming languages like C and C++ that allow text substitution before compilation, handled by a preprocessor. They are defined using directives like #define to create constants, inline functions, or conditional compilation blocks. Macros expand directly in the code, enabling code reuse and compile-time customization without runtime overhead.
Developers should learn preprocessor macros for low-level systems programming, embedded development, and performance-critical applications where compile-time optimizations are essential. They are particularly useful for defining platform-specific code, debugging with conditional compilation (e.g., #ifdef DEBUG), and creating reusable code snippets in C/C++ projects. However, they require careful use to avoid pitfalls like side effects and debugging difficulties.