in reply to Regular expression

Well, one problem is neither of your regex will match your string; the first will match strings which include 0-9 seven times in succession; the second will match seven consecutive copies of 0-9 or 0- or any combination of these; neither will match 7 random digits.

First suggestion: read the Perl documentation. Your regex are valid, but won't do what you want.

Second, and more helpful suggestion try:

/^\d{7}$/; which will match all strings which comprise exactly seven digits, with no non-numeric characters.

gOn's insertion of code tags made my entire reply nonsense

emc

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Re^2: Regular expression
by dsb (Chaplain) on Dec 09, 2005 at 18:39 UTC
    Well, one problem is neither of your regex will match your string; the first will match strings which include 0-9 seven times in succession; the second will match seven consecutive copies of 0-9 or 0- or any combination of these; neither will match 7 random digits.
    I'm not sure why you are saying that, but the OP's first pattern WILL match 7 random digits. The second will also match 7 random digits, but it will also match 1-6 random digits as well.

    Unfortunately, the OP is a bit unclear as to whether this sequence of 7 numbers should be isolated or part of a larger string.

    dsb
    This @ISA my( $cool ) %SIG
[reply]

      The square braces weren't there when I wrote my reply; I think g0n inserted the code tags after my comment. 0-90-9... does look a bit different from [0-9][0-9]; and I managed to get confused.

      emc

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