Regular Expressions
A regular expression is a character sequence that specifies a pattern of
a string. It can be used to find and replace strings.
| String |
|
\^ |
Start of string, or start of line in multi-line pattern |
\A |
Start of string |
\$ |
End of string, or end of line in multi-line pattern |
\Z |
End of string |
\b |
Word boundary |
\B |
Not word boundary |
< |
Start of word |
\> |
End of word |
| Character |
Class |
\c |
Control character |
\s |
White space, same as [ \t\n\r\f\v] |
\S |
Not white space |
\d |
Digit, same as [0-9] |
\D |
Not digit |
\w |
Word, same as [a-zA-Z_] |
\W |
Not word |
\x |
Hexadecimal digit |
\O |
Octal digit |
| Character |
Class |
. |
any character |
\n |
Newline |
\t |
tab |
| Quantifiers |
|
? |
0 or 1 |
* |
0 or more |
+ |
1 or more |
{3} |
Exactly 3 |
{3,} |
3 or more |
{3,5} |
3, 4 or 5 |
| Groups |
Description |
(...) |
Active Group |
(?:...) |
Passive (non-capturing) group |
(?=...) |
look-ahead (passive) |
(?!...) |
negative look-ahead (passive) |
(?<=...) |
look-behind (passive) |
(?!=...) |
negative look-behind (passive) |
(?<!...) |
negative look-behind (passive) |
(?>...) |
once (active) |
Examples
| Match |
Pattern |
Regex |
| Date |
YYYY-MM-DD |
\d{4}-\d{2}-\d{2} |
| Email |
xx@xx.xx |
\S{1,}@\S{2,}\.\S{2,} |
| IPv4 |
ddd.ddd.ddd.ddd |
(?:[0-9]{1,3}\.){3}[0-9]{1,3} |
Applet
Your RegEx:
\([^)]*\)">
Found Matches: