Every C program needs a main function — that is where the C runtime hands control to your code. But what if you want to write a program without typing main in the source? The answer is a preprocessor macro: #define maps any identifier you choose to main before compilation, so the compiler and linker …
C preprocessor directives are instructions that run before compilation. The preprocessor reads your source file, processes every line that starts with #, and hands the result to the compiler. Understanding them well means smaller code, safer constants, conditional compilation for different platforms, and header files that include safely more than once. Object-Like Macros — #define …
C preprocessor directives are instructions that run before compilation. The preprocessor reads your source file, processes every line that starts with #, and hands the result to the compiler. Understanding them well means smaller code, safer constants, conditional compilation for different platforms, and header files that include safely more than once. Object-Like Macros — #define …