ISO/IEC 9,899:2011 clause 6.4.2--identifiers

6.4.2 identifier

6.4.2.1 Universal

Grammar

1,identifier:

identifier-nodigit

identifier identifier-nondigit

identifier Digit

identifier-nondigit:

Nondigit

Universal-character-name

Other implementation-defined characters

nondigit: One of the following characters

_ A to Z A to Z

Digit: 0 to 9

Semantic

2, an identifier is a non-numeric (including underscores _, lowercase and uppercase Latin alphabet, and other characters) and a sequence of numbers, which assigns one or more entities described in 6.2.1. There is a difference between lowercase and uppercase letters. There is no specific limit for the maximum length of an identifier.

3.

ISO/IEC 9,899:2011 clause 6.4.2--identifiers