In C programming language, programmers can specify their name to a variable, array, pointer, function, etc... An identifier is a collection of characters which acts as the name of variable, function, array, pointer, structure, etc... In other words, an identifier can be defined as the user-defined name to identify an entity uniquely in the c programming language that name may be of the variable name, function name, array name, pointer name, structure name or a label.
The identifier is a user-defined name of an entity to identify it uniquely during the program execution
Here, marks and studentName are identifiers.
Rules for Creating Identifiers
- An identifier can contain letters (UPPERCASE and lowercase), numerics & underscore symbol only.
- An identifier should not start with a numerical value. It can start with a letter or an underscore.
- We should not use any special symbols in between the identifier even whitespace. However, the only underscore symbol is allowed.
- Keywords should not be used as identifiers.
- There is no limit for the length of an identifier. However, the compiler considers the first 31 characters only.
- An identifier must be unique in its scope.
Rules for Creating Identifiers for better programming
The following are the commonly used rules for creating identifiers for better programming...
- The identifier must be meaningful to describe the entity.
- Since starting with an underscore may create conflict with system names, so we avoid starting an identifier with an underscore.
- We start every identifier with a lowercase letter. If an identifier contains more than one word then the first word starts with a lowercase letter and second word onwards first letter is used as an UPPERCASE letter. We can also use an underscore to separate multiple words in an identifier.