Quantifiers add optional quantity data to a regular expression. A quantifier expression applies to the character, group, or character class that immediately precedes it.
The following table describes the metacharacters that affect matching quantity:
Table B.5 | List of Quantifiers |
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*
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Specifies zero or more matches; for example, \w* or (abc)*. Same as {0,}.
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+
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Specifies one or more matches; for example, \w+ or (abc)+. Same as {1,}.
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?
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Specifies zero or one matches; for example, \w? or (abc)?. Same as {0,1}.
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{n}
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Specifies exactly n matches; for example, (pizza){2}.
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{n,}
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Specifies at least n matches; for example, (abc){2,}.
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{n,m}
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Specifies at least n, but no more than m, matches.
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