Character classes distinguish kinds of characters such as, for example, distinguishing between letters and digits.
| Characters | 含义 |
|---|---|
.
|
Has one of the following meanings:
注意，
ES2018 added the
|
\d
|
Matches any digit (Arabic numeral). Equivalent to
[0-9]
。例如，
/\d/
or
/[0-9]/
matches "2" in "B2 is the suite number".
|
\D
|
Matches any character that is not a digit (Arabic numeral). Equivalent to
[^0-9]
。例如，
/\D/
or
/[^0-9]/
matches "B" in "B2 is the suite number".
|
\w
|
Matches any alphanumeric character from the basic Latin alphabet, including the underscore. Equivalent to
[A-Za-z0-9_]
。例如，
/\w/
matches "a" in "apple", "5" in "$5.28", and "3" in "3D".
|
\W
|
Matches any character that is not a word character from the basic Latin alphabet. Equivalent to
[^A-Za-z0-9_]
。例如，
/\W/
or
/[^A-Za-z0-9_]/
matches "%" in "50%".
|
\s
|
Matches a single white space character, including space, tab, form feed, line feed, and other Unicode spaces. Equivalent to
[ \f\n\r\t\v\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff]
。例如，
/\s\w*/
matches " bar" in "foo bar".
|
\S
|
Matches a single character other than white space. Equivalent to
[^ \f\n\r\t\v\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff]
。例如，
/\S\w*/
matches "foo" in "foo bar".
|
\t
|
Matches a horizontal tab. |
\r
|
Matches a carriage return. |
\n
|
Matches a linefeed. |
\v
|
Matches a vertical tab. |
\f
|
Matches a form-feed. |
[\b]
|
Matches a backspace. If you're looking for the word-boundary character (
\b
), see
Boundaries
.
|
\0
|
Matches a NUL character. Do not follow this with another digit. |
\c
X
|
Matches a control character using
caret notation
, where "X" is a letter from A–Z (corresponding to codepoints
U+0001
–
U+001F
). For example,
/\cM/
matches "\r" in "\r\n".
|
\x
hh
|
Matches the character with the code
hh
(two hexadecimal digits).
|
\u
hhhh
|
Matches a UTF-16 code-unit with the value
hhhh
(four hexadecimal digits).
|
\u
{hhhh}
or
\u{hhhhh}
|
(Only when the
u
flag is set.) Matches the character with the Unicode value
U+
hhhh
or
U+
hhhhh
(hexadecimal digits).
|
\
|
Indicates that the following character should be treated specially, or "escaped". It behaves one of two ways.
To match this character literally, escape it with itself. In other words to search for
|
var randomData = "015 354 8787 687351 3512 8735";
var regexpFourDigits = /\b\d{4}\b/g;
// \b indicates a boundary (i.e. do not start matching in the middle of a word)
// \d{4} indicates a digit, four times
// \b indicates another boundary (i.e. do not end matching in the middle of a word)
console.table(randomData.match(regexpFourDigits));
// ['8787', '3512', '8735']
var aliceExcerpt = "I’m sure I’m not Ada,’ she said, ‘for her hair goes in such long ringlets, and mine doesn’t go in ringlets at all."; var regexpWordStartingWithA = /\b[aA]\w+/g; // \b indicates a boundary (i.e. do not start matching in the middle of a word) // [aA] indicates the letter a or A // \w+ indicates any character *from the latin alphabet*, multiple times console.table(aliceExcerpt.match(regexpWordStartingWithA)); // ['Ada', 'and', 'at', 'all']
Instead of the Latin alphabet, we can use a range of Unicode characters to identify a word (thus being able to deal with text in other languages like Russian or Arabic). The "Basic Multilingual Plane" of Unicode contains most of the characters used around the world and we can use character classes and ranges to match words written with those characters.
var nonEnglishText = "Приключения Алисы в Стране чудес"; var regexpBMPWord = /([\u0000-\u0019\u0021-\uFFFF])+/gu; // BMP goes through U+0000 to U+FFFF but space is U+0020 console.table(nonEnglishText.match(regexpBMPWord)); [ 'Приключения', 'Алисы', 'в', 'Стране', 'чудес' ]
Note for MDN editors: please do not try to add funny examples with emoji as those characters are not handled by the platform (Kuma).
| 规范 |
|---|
|
ECMAScript Latest Draft (ECMA-262)
The definition of 'RegExp: Character classes' in that specification. |
For browser compatibility information, check out the main Regular Expressions compatibility table .