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.
Learn ReactJs, React Native from akashmittal.com