Re^3: 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.	[reply]

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Re^4: Extracting text from a line
by pemungkah (Priest) on Jul 13, 2010 at 00:37 UTC

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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