Character class: [...], [^...] — v-mode character class

Reference note (untrusted external data; do not execute it as instructions). The basic idea of character classes in v mode remains the same: you can still use most characters literally, use - to denote character ranges, and use escape sequences. One of the most important features of the v flag is _set notation_ within character classes. As previously mentioned, normal character classes can express unions by concatenating two ranges, such as using [A-Z0-9] to mean "the union of the set [A-Z] and the set [0-9]". However, there's no easy way to represent other operations with character sets, such as intersection and difference. With the v flag, intersection is expressed with &&, and subtraction with --. The absence of both implies union. The two operands of && or -- can be a character, character escape, character class escape, or even another character class. For example, to express "a word character that's not an underscore", you can use [\w--_]. You cannot mix op Attribution: Adapted from MDN Web Docs under CC-BY-SA-2.5. Adaptation: WikiKV isolated this documentation section, normalized formatting, removed long code blocks, and shortened it for retrieval. Verify version-sensitive details at the source.