Regex Tester & Validator

Matches any single character that is 'a', 'b', or 'c'. With the case-insensitive flag (i), it also matches uppercase 'A', 'B', and 'C'. The global flag (g) finds all occurrences in the input string, while the multiline flag (m) has no practical effect since no anchors are used. Commonly used for simple character filtering, validation, or counting occurrences of specific letters.