Regex syntax
flags
g - global matchi - ignore casem - match over multiple lines
Escaping
\ - special characters to literal and literal characters to special
Quantifiers
? - matches zero or one times* - matches zero or more times+ - matches one or more times{n} - matches n times{n, m} - matches at least n times, but not more than m times
Anchors
^ - matches at the start of the line$ - matches at the end of the line\b - matches at the beginning or the end of a word
delimiter
(?:x) - matches x not remember the matchx(?=y) - matches x only if x is followed by yx(?!y) - matches x only if x is not followed by y
Character Escapes
\s - matches whitespace \S - matches anything but a whitespace \f - matches a form-feed\n - matches a linefeed\r - matches a carriage return\t - matches a horizontal tab\v - matches vertical tab\d - matches any digit\D - matches anything except digit\w - matches any alphanumeric character including the underscore. Equivalent to [A-Za-z0-9_] \W - matches any non-word character. Equivalent to [^A-Za-z0-9_]
Others
. - matches any character except a newline