Regex lookahead, lookbehind and atomic groups

Examples Given the string foobarbarfoo: You can also combine them: Definitions Look ahead positive (?=) Find expression A where expression B follows: Look ahead negative (?!) Find expression A where expression B does not follow: Look behind positive (?<=) Find expression A where expression B precedes: Look behind negative (?<!) Find expression A where expression B does not precede: Atomic … Read more