Identifiers in C Programming

Identifier refers to name given to entities such as variables, functions, structures, etc.

Identifiers must be unique. They are created to give a unique name to an entity to identify it during the execution of the program. For example:

int money;

double accountBalance;

Here, money and accountBalance are identifiers.

Also remember, identifier names must be different from keywords. You cannot use int as an identifier because int is a keyword.

Rules for naming identifiers:-

• A valid identifier can have letters (both uppercase and lowercase letters), digits, and underscores.

• The first letter of an identifier should be either a letter or an underscore.

• You cannot use keywords as identifiers.

• There is no rule on how long an identifier can be. However, you may run into problems in some compilers if the identifier is longer than 31 characters.

• You can choose any name as an identifier if you follow the above rule, however, give meaningful names to identifiers that make sense.