An identifier is a sequence of characters in the code that identifies a , , or . In most languages, identifiers are case-sensitive and not quoted.

In , identifiers can contain letters, $, _, and digits (0-9), but may not start with a digit. An identifier differs from a string in that a is data, while an identifier is part of the code. In JavaScript, there is no way to convert identifiers to strings, but sometimes it is possible to parse strings into identifiers.

In , there are two identifier data types: and . The CSS can contain almost any character, but non-letter/digit ASCII characters such as ", \, and * must be escaped, it must not start with a digit, and emojis are valid as identifiers that do not require escaping.

See also

Related glossary terms:

• Identifier on Wikipedia