Very Simple jQuery based regular expression testing tool. Use this tool to create and test regular expression pattern on string.
| Meta Characters | |
|---|---|
| ^ | Start of subject (or line in multiline mode) |
| $ | End of subject (or line in multiline mode) |
| [ | Start character class definition |
| ] | End character class definition |
| | | Alternates ( a|b matches a or b ) |
| ( | Start subpattern |
| ) | End subpattern |
| \ | Escape character |
| Base Character Classes | |
|---|---|
| \w | Any "word" character (a-z 0-9 _) |
| \W | Any non-"word" character |
| \s | Whitespace (space, tab, CRLF) |
| \S | Any non-whitespace character |
| \d | Digits (0-9) |
| \D | Any non-digit character |
| . | Any character except newline |
| Quantifiers | |
|---|---|
| * | Zero or more |
| + | One or more |
| ? | Zero or one occurrence |
| {n} | n occurrences exactly |
| {n,} | At least n occurrences |
| {,m} | At most m occurrences |
| {n,m} | Between n and m occurrences inclusive |
| Subpatern Modifiers & Assertions | ||
|---|---|---|
| (?:) | Non capturing subpattern | ((?:foo|fu)bar) matches foobar or fubar without foo or fu appearing as a captured subpattern |
| (?=) | Positive look ahead assertion | foo(?=bar) matches foo when followed by bar |
| (?!) | Negative look ahead assertion | foo(?!bar) matches foo when not followed by bar |
| (?<=) | Positive look behind assertion | (?<=foo)bar matches bar when preceded by foo |
| (?<!) | Negative look behind assertion | (?<!foo)bar matches bar when not preceded by foo |
| (?>) | Once-only subpatterns | (?>\d+)bar Performance enhancing when bar not present |
| (?(x)) | Conditional subpatterns | (?(3)foo|fu)bar Matches foo if 3rd subpattern has matched, fu if not |