Num has no special meaning in C language. It is neither a keyword nor a function name of a library function.

It can be a programmer-defined variable name or function name.

Variables that are usually used to define numeric types are the first three letters of numbers in English.

Examples are as follows:

Int num// defines an int variable named num.

Double num// defines a variable of type Double named num.

Intnum (int a, int b)//Customize a function named num.

{

Return a+b;

}