1/* shorthand character classes */
2regex = /d/; // matches any digit, short for [0-9]
3regex = /D/; // matches non-digits, short for [^0-9]
4regex = /S/; // matches non-white space character
5regex = /s/; // matches any white space character
6regex = /w/; // matches character, short for [a-zA-Z_0-9]
7regex = /W/; // matches non-word character [^w]
8regex = /b/; // Matches a word boundary where a word character is [a-zA-Z0-9_]