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Re^3: Extracting text from a line

by almut (Canon)
on Jul 12, 2010 at 07:28 UTC ( #848938=note: print w/ replies, xml ) Need Help??

in reply to Re^2: Extracting text from a line
in thread Extracting text from a line

What's the difference, semantically?

Note that in list context (my ($uid) = ...), the match operation returns the captures, so $uid holds the same value as $1.  If there is no match, both values are undef.

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Re^4: Extracting text from a line
by pemungkah (Priest) on Jul 13, 2010 at 00:37 UTC
    Vivek, I strongly disagree with you here because of the fact that the number variables are very fragile: they are global to every pattern match.

    If someone else comes along and adds (for instance) a"harmless" subroutine call that sometimes does a pattern match of its own between the match and the usage of $1, then the results are unpredictable because the intervening match has reused the global variables.

    If you always capture the value in a separate variable immediately, you're safe from this potential bug.

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