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 concluded it means the …

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 fewer rep at …

What are ^.* and .*$ in regular expressions? Asked 14 years, 1 month ago Modified 2 years, 7 months ago Viewed 233k times

What's the difference between () and [] in regular expression patterns? Asked 15 years, 3 months ago Modified 2 years, 10 months ago Viewed 145k times

Jul 6, 2009 · 36 Regular expressions first came around in mathematics and automata theory. A regular expression is simply something which defines a regular language. Without going too much into what …

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

May 15, 2010 · What does \d+ mean in a regular expression? Asked 15 years, 8 months ago Modified 3 years, 4 months ago Viewed 286k times

886 Take this regular expression: /^[^abc]/. This will match any single character at the beginning of a string, except a, b, or c. If you add a * after it – /^[^abc]*/ – the regular expression will continue to add …

A regular expression can only act as a rudimentary filter. The problem with regular expressions is that telling someone that their perfectly valid e-mail address is invalid (a false negative) because your …

Examples of regular expressions The following examples illustrate the use and construction of simple regular expressions. Each example includes the type of text to match, one or more regular …