Read: 04

Responsive Web Design/Regular Expressions

Character 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 characters

• .*\ 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