Identifiers are user defined words and refer to the names of variable, function arrays, structure,etc. It consist of a sequence of letters and digits with a letter as a first character. Both uppercase letters and lowercase letters are permitted, although lowercase letters are commonly used.
Rules of Identifiers:
- First character must be an alphabet or underscore.
- Must consist only uppercase and lowercase letters, digits and underscore sign.
- A keyword cannot be use.
- Only implementations 31 character, that are recognize by ANSI standard.
- Most not contain white space.
Some examples of valid identifier:-
a age NAME _space new1 white-space
Some example of invalid identifier:-
1new First character must be an alphabet or underscore.
int A keyword cannot be use.
note# # is a special character.
no 1 blank space is not permitted.