Check out example codes for "c define". It will help you in understanding the concepts better.

Code Example 1

#define CNAME value

Code Example 2

#define SIZE 42
#define MSG "Hello, World!"

Code Example 3

#define is a C preprocessor directive used to define macros. ... The preprocessor directives are used to provide general instruction or required data which is used inside a program. A macro is a block of code which has been given a name. Any occurance of that name is replaced by the value of the macro.

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