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.

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 string $ …

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

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 match of …

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

Normally the dot matches any character except newlines. So if .* isn't working, set the "dot matches newlines, too" option (or use (?s).*). If you're using JavaScript, which doesn't have a "dotall" option, …

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.

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.

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 well as …

The regex [a-z] will match any letter a through z. The () construct is a grouping construct establishing a precedence order (it also has impact on accessing matched substrings but that's a bit more of an …