Regex Tester & Validator

This PCRE2 regex matches a JSON property named "asento" (Finnish for "position") where the assigned value is anything other than the exact string values "vasen" (left) or "oikea" (right). It utilizes a character-by-character negative lookahead to ensure the captured value does not equal these restricted strings, ending right before a trailing comma and the end of the line. This is particularly useful for validating JSON lines or filtering out records that contain specific disallowed states.