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

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 …

Oct 15, 2009 · What is the literal meaning of this regex that contains a lookahead? 52. Reference - What does this regex ...

Sep 13, 2015 · Let's deconstruct your regex (I removed the backslashes that are used to escape characters for the sake of simplification, we will use the dots and slashes as literal here) so …

Dec 8, 2018 · If efficiency were a consideration, would be better off coding the operation by hand instead of using regex's, rather than accept the efficiency gain of capturing vs. non capturing …

On greedy vs non-greedy. 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 …

Oct 24, 2011 · Now, by default, the RegEx e will find the third letter e in word There. There ^ However if you don't want the e which is immediately followed by r, then you can use RegEx …

Dec 17, 2012 · So, the String before the $ would of course not include the newline, and that is why ([A-Za-z ]+\n)$ regex of yours failed, and ([A-Za-z ]+)$\n succeeded. In simple words, …

Fast regexen also need an "anchor" point, somewhere to start it's search somewhere in the string. These characters tell the Regex engine where to start looking and generally reduce the …

Nov 30, 2011 · That looks like a typical password validation regex, except it has couple of errors. First, the .* at the beginning doesn't belong there. If any of those lookaheads doesn't succeed …