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正则表达式速查

正则表达式元字符·标志·类的交互式参考

all
meta
quantifier
class
anchor
group
lookaround
flag

38 entries

meta
.

Any single character except newline

a.c → 'abc'

meta
\d

Digit (0-9)

\d+ → '123'

meta
\D

Non-digit

\D+ → 'abc'

meta
\w

Word char [A-Za-z0-9_]

\w+ → 'foo_1'

meta
\W

Non-word char

\W → '!'

meta
\s

Whitespace (space, tab, newline)

a\sb → 'a b'

meta
\S

Non-whitespace

\S+ → 'foo'

meta
\b

Word boundary

\bcat\b → 'cat'

meta
\B

Non-word boundary

\Bcat → 'concat'

quantifier
*

0 or more (greedy)

a* → '', 'aaa'

quantifier
+

1 or more (greedy)

a+ → 'aaa'

quantifier
?

0 or 1 (optional)

colou?r → 'color', 'colour'

quantifier
{n}

Exactly n times

\d{4} → '2025'

quantifier
{n,}

n or more times

\d{2,} → '12', '123'

quantifier
{n,m}

Between n and m times

\d{2,4} → '12', '1234'

quantifier
*?

0 or more (lazy)

<.*?> → '<a>', '<b>'

quantifier
+?

1 or more (lazy)

.+? → minimal match

class
[abc]

Any one of a, b, c

[aeiou] → vowels

class
[^abc]

None of a, b, c

[^0-9] → non-digit

class
[a-z]

Range a to z

[A-Za-z] → letters

class
[\d\s]

Combined classes

[\d\.] → digit or dot

anchor
^

Start of string (or line with /m)

^foo → starts with foo

anchor
$

End of string (or line with /m)

bar$ → ends with bar

group
(abc)

Capturing group

(\d+)-(\w+) → captures both

group
(?:abc)

Non-capturing group

(?:foo|bar)+

group
(?<name>abc)

Named capture group

(?<year>\d{4})

group
a|b

Alternation (or)

cat|dog → 'cat' or 'dog'

group
\1

Backreference to group 1

(\w)\1 → 'oo' in 'book'

lookaround
(?=abc)

Positive lookahead

\d(?=px) → '12' in '12px'

lookaround
(?!abc)

Negative lookahead

\d(?!px) → digit not followed by px

lookaround
(?<=abc)

Positive lookbehind

(?<=\$)\d+ → '100' in '$100'

lookaround
(?<!abc)

Negative lookbehind

(?<!\$)\d+ → digit not after $

flag
g

Global — all matches

/foo/g

flag
i

Case-insensitive

/FOO/i → matches 'foo'

flag
m

Multiline — ^/$ per line

/^line/m

flag
s

Dotall — . matches newline

/a.b/s

flag
u

Unicode mode

/\u{1F600}/u

flag
y

Sticky — match from lastIndex

/foo/y

使用方法

  1. 在搜索框中输入关键字，如"lookahead"、"quantifier"或 "\d"以过滤条目。
  2. 点击类别徽章以将结果范围缩小到锚点、组、量词、类或前看。
  3. 点击任何卡片以将其语法复制到剪贴板。
  4. 使用底部的复制链接按钮分享您的过滤视图。

示例

  • 搜索"lookahead"将列表范围缩小到 (?=...) 和 (?!...) 条目，带有描述和示例。
  • 点击量词徽章显示 +、*、?、{n,m} 等条目 — 每张卡片显示语法、描述和短示例字符串。

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