To elaborate on the previous answer, Perl's regex engine finds the left-most match, stopping as soon as it gets a match. In this case that is the zero-length string at the beginning of your text. Other regex engines are different - some prefer the longest possible match, which would have yielded your expected "1000".

A good book about regexes is Mastering Regular Expressions, which answers this question in much more detail and many others. I highly recommend it for all Perl programmers.

-sam

In reply to Re: question about the star(*) quantifier by samtregar
in thread question about the star(*) quantifier by snowsky

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