Javascript regex
Wednesday, August 8, 2018
8:42 AM
Python
JavaScript Regex Cheatsheet
Regular Expression Basics
.
Any character except newline
a
The character a
ab
The string ab
a|b
a or b
a*
0 or more a's
\
Escapes a special character
Regular Expression Quantifiers
*
0 or more
+
1 or more
?
0 or 1
{2}
Exactly 2
{2, 5}
Between 2 and 5
{2,}
2 or more
Default is greedy. Append ? for reluctant.
Regular Expression Groups
(...)
Capturing group
(?:...)
Non-capturing group
\Y
Match the Y'th captured group
Regular Expression Character Classes
[ab-d]
One character of: a, b, c, d
[^ab-d]
One character except: a, b, c, d
[\b]
Backspace character
\d
One digit
\D
One non-digit
\s
One whitespace
\S
One non-whitespace
\w
One word character
\W
One non-word character
Regular Expression Assertions
^
Start of string
$
End of string
\b
Word boundary
\B
Non-word boundary
(?=...)
Positive lookahead
(?!...)
Negative lookahead
Regular Expression Flags
g
Global Match
i
Ignore case
m
^ and $ match start and end of line
Regular Expression Special Characters
\n
Newline
\r
Carriage return
\t
Tab
\0
Null character
\YYY
Octal character YYY
\xYY
Hexadecimal character YY
\uYYYY
Hexadecimal character YYYY
\cY
Control character Y
Regular Expression Replacement
$$
Inserts $
$&
Insert entire match
$`
Insert preceding string
$'
Insert following string
$Y
Insert Y'th captured group