Regex with all optional parts but at least one required

Question

I need to write a regex that matches strings like \"abc\", \"ab\", \"ac\", \"bc\", \"a\", \"b\", \"c\". Order is important and it shouldn\'t match multiple appearances of th

Answer 1

^(?=.)a?b?c?$

This will check if there is at least one character with lookahead and will match your regex.