REG_EXR.md

RegEx cheatsheet

##How to write / (start), regEx, /gi (global insensitive)
ex:

• /b\w{2,3}/gi: matches any word containing a b with 2 others letters and cut the word at 3 other letter (+insensitive & global)
• b(a|e|i)d: starts with b end with d & contains a or e or i

Char classes

. any character except newline \w\d\s word, digit, whitespace \W\D\S not word, digit, whitespace [abc] any of a, b, or c [^abc] not a, b, or c [a-g] character between a & g

Anchors

^abc$ start/end of the string \b\B word, not-word boundary

Escaped chars

\.\*\\ escaped special characters \t\n\r tab, linefeed, carriage return

Groups & lookaround

(abc) capture group \1 backreference to group #1 (?:abc) non-capturing group (?=abc) positive lookahead (?!abc) negative lookahead

Quantifiers & Alternation

a*a+a? 0 or more, 1 or more, 0 or 1 a{5}a{2,} exactly five, two or more a{1,3} between one & three a+?a{2,}? match as few as possible ab|cd match ab or cd