In C, C++, C# and other programming languages, an identifier is a name that is assigned by the user for a program element such as variable, type, template, class, function or namespace. It is usually limited to letters, digits, and underscores. ... You designate an identifier by declaring it early in the code.

How does an identifier work?

An identifier may be a word, number, letter, symbol, or any combination of those. The words, numbers, letters, or symbols may follow an encoding system (wherein letters, digits, words, or symbols stand for (represent) ideas or longer names) or they may simply be arbitrary.

What is identifier in C rules?

Identifiers are the user-defined names consisting of 'C' standard character set. ... a) An identifier can only have alphanumeric characters (a-z , A-Z , 0-9) (i.e. letters & digits) and underscore( _ ) symbol. b) Identifier names must be unique c) The first character must be an alphabet or underscore.