Reference

Name	Description	Example
g	global boundary	/[a-z]/g
globle	test g is or not
i	case-insensitive	/[a-z]/i
ignoreCase	test i is or not
.	any character except newline	/*/
\w	word equal to [A-z]	/\w/
\W	not word equal to []*%$@# etc	/\W/
\d	digit equal to [0-9]	/\d/
\D	not digit equal to anything except for [0-9]	/\D/
\s	whitespace	/\s/
\S	not whitespace	/\S/
[ABC]	select A, B or C; if it's [D], select D	/[ABC]/
[^ABC]	not select A, B or C; select others	/[^ABC]/
\b	select a word the last alphabet	/ed\b/
\D	select a word not the last alphabet	/ed\D/
^	start	/^ed/
$	end	/ed$/