In computer science, a preprocessor (or precompiler) is a program that processes its input data to produce output that is used as input to another program. … A common example from computer programming is the processing performed on source code before the next step of compilation.

What is preprocessor in C with example?

The C preprocessor is a macro processor that is used automatically by the C compiler to transform your program before actual compilation (Proprocessor direcives are executed before compilation.). … For example, #define is the directive that defines a macro. Whitespace is also allowed before and after the # .

What is preprocessor commands in C?

In C programming language, preprocessor directive is a step performed before the actual source code compilation. When we try to compile a program, preprocessor commands are executed first and then the program gets compiled. … Every preprocessor command begins with # symbol.