C Language Zemi

Preprocessor

A preprocessor is a program that replaces source code before compiling C language. Before compiling, to be more specific, before lexical analysis begins. Called automatically by the C language compiler.

Preprocessor instructions

Preprocessor instructions are instructions that the preprocessor has. Frequently used items include "#include" and "#define".

• #include --File include
• Macro description with #define
• Function macro with #define
• Preprocessor conditional branching

Predefined macros

• __FILE__ --filename
• __LINE__ --line number