Tham khảo Regex
Lớp Ký tự
| Cú pháp | Tên | Mô tả | Ví dụ |
|---|---|---|---|
. | Any char | Matches any single character except newline | .at → hat,cat,mat |
\d | Digit | Matches any digit | \d{3} → 123,456 |
\D | Non-digit | Matches any non-digit | \D → a,b,! |
\w | Word char | Letter,digit or underscore | \w+ → hello_world |
\W | Non-word | Any non-word char | \W → @,#,! |
\s | Whitespace | Space,tab,newline | \s → space,tab |
\S | Non-whitespace | Any non-whitespace | \S → a,1,X |
[abc] | Char set | Matches any char in brackets | [aeiou] → a,e,i,o,u |
[^abc] | Negated set | Matches chars NOT in brackets | [^0-9] → a,b,! |
[a-z] | Range | Matches any char in range | [A-Z] → A,B,C |
\n\t\r | Escapes | Control characters | \n → newline |
Lượng từ
| Cú pháp | Tên | Mô tả | Ví dụ |
|---|---|---|---|
* | 0 or more | 0+ occurrences, greedy | a* → "",a,aa,aaa |
+ | 1 or more | 1+ occurrences | a+ → a,aa,aaa |
? | Optional | 0 or 1 | colou?r → color,colour |
{n} | Exactly n | Exactly n times | \d{3} → 123,456 |
{n,} | n or more | n+ times | \d{2,} → 12,12345 |
{n,m} | n to m | Between n and m | \d{2,4} → 12,123,1234 |
*? | Lazy star | 0+, as few as possible | a.*?b → ab,aXb |
+? | Lazy plus | 1+, as few as possible | a.+?b → aXb,aXYb |
Neo
| Cú pháp | Tên | Mô tả | Ví dụ |
|---|---|---|---|
^ | Start | Start of string/line | ^Hello → Hello world |
$ | End | End of string/line | end$ → the end |
\b | Word boundary | Between word and non-word | \bcat\b → cat not catch |
\B | Non-boundary | Not at word boundary | \Bcat → location |
Nhóm
| Cú pháp | Tên | Mô tả | Ví dụ |
|---|---|---|---|
(...) | Capture group | Captures for backreference | (ab)+ → ababab |
(?:...) | Non-capture | Groups without capture | (?:ab)+ → matches,no capture |
(?=...) | Lookahead | Asserts what follows | foo(?=bar) → foobar |
(?!...) | Negative lookahead | Asserts what does NOT follow | foo(?!bar) → food not foobar |
| | Alternation | OR | cat|dog → cat or dog |
\1 | Backreference | Same text as group 1 | (\w)\1 → aa,bb,cc |
Cờ
| Cú pháp | Tên | Mô tả | Ví dụ |
|---|---|---|---|
g | Global | All matches | /cat/g → all matches |
i | Case insensitive | Ignore case | /cat/i → Cat,CAT,cat |
m | Multiline | ^ and $ per line | ^ and $ match each line |
u | Unicode | Unicode support | Unicode support |
s | Dotall | dot matches newline | . matches newline too |
Thông dụng
| Cú pháp | Tên | Mô tả | Ví dụ |
|---|---|---|---|
\d{3}-\d{4} | Phone | Phone number format | 010-1234 |
[\w.-]+@[\w-]+\.[a-z]{2,} | Email address | [email protected] | |
https?://[\w.-]+ | URL | Web URL | https://example.com |
\d{4}-\d{2}-\d{2} | Date | YYYY-MM-DD | 2024-01-15 |
[A-Z][a-z]+ | Capitalized | Capitalized words | Hello,World |
#[0-9a-fA-F]{6} | Hex color | 6-digit hex color | #FF6600,#ff6600 |