Re^3: Announcing Perl-Critic-0.14

Please forgive my ignorance, but what's wrong with it? $foo ends up as 1 when $bar is true and is undefined when $bar is false. Just as I expect it to be. (Active Perl 5.8.7)

Wrong. This piece of code is one of the weird things in perl, in this case, something that is sometimes used as a dirty trick, to create a static variable.

#!/usr/bin/perl -lw
print $];
for (1 .. 5) {
    my $i = 123 if $bar;
    print ++$i;
}
[download]

Result:

Name "main::bar" used only once: possible typo at test.pl line 4.
5.008003
1
2
3
4
5
[download]

Comment on Re^3: Announcing Perl-Critic-0.14 Select or Download Code

Replies are listed 'Best First'.
Re^4: Announcing Perl-Critic-0.14 by holli (Abbot) on Jan 30, 2006 at 17:26 UTC
Conclusion: Always assign something in a `my` declaration? The following works as expected. `my $i = $bar ? 123 : undef;` [download] And yeah, that's really weird. holli, /regexed monk/	[reply] [d/l] [select]
Re^5: Announcing Perl-Critic-0.14 by Aristotle (Chancellor) on Jan 30, 2006 at 17:59 UTC
Conclusion: Always assign something in a `my` declaration? More precisely: make sure an assignment with a `my` on the left-hand side is never conditional. Makeshifts last the longest.	[reply] [d/l] [select]
Re^6: Announcing Perl-Critic-0.14 by diotalevi (Canon) on Jan 30, 2006 at 21:08 UTC
It's not about the assignment. It's that my() should never be conditional. `my $foo if $bar` is just as bad for the same reason. You're just not likely to write that because it looks funny. `my $foo ... for ...` is probably also just as bad. The statement modifier form allows the my() to declare the variable for use by all following statements in that scope. ⠤⠤ ⠙⠊⠕⠞⠁⠇⠑⠧⠊	[reply] [d/l] [select]
Re^5: Announcing Perl-Critic-0.14 by ysth (Canon) on Jan 30, 2006 at 18:43 UTC
Always assign something in a my declaration? I think it boils down to: Never modify a lexical unless the my() was executed during the current execution of the enclosing block.	[reply]


Problems? Is your data what you think it is?
	PerlMonks