C Macros

A macro is a segment of code which is replaced by the value of macro. Macro is defined by #define directive. There are two types of macros:

1. Object-like Macros
2. Function-like Macros

Object-like Macros

The object-like macro is an identifier that is replaced by value. It is widely used to represent numeric constants. For example:

Here, PI is the macro name which will be replaced by the value 3.14.

Function-like Macros

The function-like macro looks like function call. For example:

Here, MIN is the macro name.

Visit #define to see the full example of object-like and function-like macros.

C Predefined Macros

ANSI C defines many predefined macros that can be used in c program.

C predefined macros example

File: simple.c

Output:

File :simple.c
Date :Dec 6 2015
Time :12:28:46
Line :6
STDC :1