The following is more for the benefit gayu_justin than for kcott:
Consider what might happen if you wanted to use the $user->id version of $usr after the loop. By using my when you start the loop (as I did) you get a different variable (scoped to the loop) and avoid possible future problems.
This is an oddity, IMHO, of the way for-loop variables behave. The variable is fully localized even though it is lexical. So this code doesn't work as one (I myself, on more than one occasion) would naively expect:
>perl -wMstrict -le "my $max_x = 99; ;; for $max_x (0 .. 5) { print $max_x; last if $max_x == 2; } ;; print qq{max_x: $max_x}; " 0 1 2 max_x: 99
Nor does the loop variable do something really odd like becoming a package variable:
>perl -wMstrict -le "my $x = 'foo'; print qq{x before loop: '$x'}; ;; for $x (0 .. 2) { func(); our $y; print qq{$x, $y}; } ;; print qq{x after loop: '$x'}; sub func { our $x; our $y; $x = 99; $y = 42; } " x before loop: 'foo' 0, 42 1, 42 2, 42 x after loop: 'foo'
So what's the point of ever using a lexical loop variable in the for my $x (...) { ... } form? If $x was a package variable to start with, the loop variable $x would then be fully lexically scoped. Remove the my from the following example to see the difference.
>perl -wMstrict -le "our $max_x = 99; ;; for my $max_x (0 .. 4) { func(); print $max_x; last if $max_x == 2; } ;; print qq{max_x after loop: $max_x}; ;; sub func { $max_x = 42; } " 0 1 2 max_x after loop: 42
In reply to Re^2: showing the error ,Can't modify concatenation (.) or string in scalar assignment
by AnomalousMonk
in thread showing the error ,Can't modify concatenation (.) or string in scalar assignment
by gayu_justin
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