Oct 1, 2012 · In Regex, . refers to any character, be it a number, an aplhabet character, or any other special character. * means zero or more times.

In case it is JS it indicates the start and end of the regex, like quotes for strings. stackoverflow.com/questions/15661969/…

Jun 1, 2017 · Specifically when does ^ mean "match start" and when does it mean "not the following" in regular expressions? From the Wikipedia article and other references, I've …

Javascript RegExp () allows you to specify a multi-line mode (m) which changes the behavior of ^ and $. ^ represents the start of the current line in multi-line mode, otherwise the start of the …

Repetition in regex by default is greedy: they try to match as many reps as possible, and when this doesn't work and they have to backtrack, they try to match one fewer rep at a time, until a …

Oct 15, 2009 · May I know what ?= means in a regular expression? For example, what is its significance in this expression: (?=.*\\d).

Dec 8, 2018 · The regex compiles fine, and there are already JUnit tests that show how it works. It's just that I'm a bit confused about why the first question mark and colon are there.

Be aware that the first ^ in this answer gives the regex a completely different meaning: It makes the regular expression look only for matches starting from the beginning of the string.

How do I make an expression to match absolutely anything (including whitespaces)? Example: Regex: I bought _____ sheep. Matches: I bought sheep. I bought a sheep. I bought five …

By putting ^ at the beginning of your regex and $ at the end, you ensure that no other characters are allowed before or after your regex. For example, the regex [0-9] matches the strings "9" as …