RegExpr Help › Greedy and stingy
Greedy matching means that a regular expression matches as many characters as possible. Regular expressions are greedy by default.
Stingy matching or minimal matching means a regular expression will match as few characters as possible. To use stingy matching, add a question mark ? to a quantifier.
Given input "The fool is under the bar in the barn", try the following regular expressions:
| Greedy | foo.*bar | This will match "fool is under the bar in the bar". |
| Stingy | foo.*?bar | This will match "fool is under the bar". |
As you can see, .* matched as much as possible, where .*? matched only as much as was needed.
The following table lists the quantifiers that have a greedy and a stingy variant.
| x* | Zero or more x's (greedy, take as many as possible) |
| x*? | Zero or more x's (stingy, take as few as possible) |
| x+ | One or more x's (greedy, take as many as possible) |
| x+? | One or more x's (stingy, take as few as possible) |
| x? | One or zero x (greedy, try one first) |
| x?? | Zero or one x (stingy, try zero first) |
| x{m,n} | At least m and at most n x's (greedy, take as many as possible) |
| x{m,n}? | At least m and at most n x's (stingy, take as few as possible) |
| x{,n} | At most n x's (greedy, take as many as possible) |
| x{,n}? | At most n x's (stingy, take as few as possible) |
| x{n,} | At least n x's (greedy, take as many as possible) |
| x{n,}? | At least n x's (stingy, take as few as possible) |
Regular expression syntax rules
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