IDENTIFIERS

In C, the names of variables, arrays, functions, labels and various user defined items are called identifiers.

The variables, arrays, functions, etc. can be identified by giving them meaningful names.

These names are called identifiers

RULES FOR IDENTIFIERS

1. The first character of an identifier must be an alphabet or an underscore
2. Identifiers must consist of only alphabets, digits or underscore
3. Special symbos are not allowed
4. Keywords should not be used as the identifiers
5. Identifier should be a single word, i.e., No blank space is allowed
6. Identifiers can be both uppercase and lowercase. C is case sensitive, i.e., uppercase letters are different from lowercase letters

e.g : ADD , AdD, add are different identifiers

 

Valid Identifiers	Invalid Identifiers
ADD	3add	Numerics not allowed in the beginning
Add	add+123	+ is not allowed
_add	for	it is a keyword
Student_Name	ABC XYZ	Blank not allowed
Name	Student%123	% Is not allowed
A312B	_Add*5Add	* is not allowed