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Re^2: no uninitialized warnings

by busunsl (Vicar)
on Aug 25, 2004 at 12:54 UTC ( #385668=note: print w/replies, xml ) Need Help??

in reply to Re: no uninitialized warnings
in thread no uninitialized warnings

Danger, Will Robinson. Danger!

If $var1 has the value 0, it will be set to '', which might not be what you want.

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Re^3: no uninitialized warnings
by bronto (Priest) on Aug 25, 2004 at 16:14 UTC

    Mh... something like this?

    @x=(1..3) ; undef $x[1] ; $_ = defined $_? $_: '[__UNDEF__]' for @x ; print "@x" ;


    The very nature of Perl to be like natural language--inconsistant and full of dwim and special cases--makes it impossible to know it all without simply memorizing the documentation (which is not complete or totally correct anyway).
    --John M. Dlugosz

      or like this:

      $_ = '[undef]' for grep !defined, $var1, $var2, $var3; print "$var1, $var2, $var3";

      Update: I forgot that changing the values can affect program logic(as Aristotle mentioned). So, the best approach (imho) is just print with warnings or

      use Data::Dumper; print Data::Dumper->Dump([$var1, $var2, $var3], [qw(var1 var2 var3)]);

        Or non-destructively and unambiguously:

        print join " ", map { defined() ? "'\Q$_\E'" : 'undef' } $var1, $var2, + $var3;

        Makeshifts last the longest.

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[Corion]: :-D
Corion discovers a new shiny toy to try out over the (longish) weekend. Since I've done some more with websockets, maybe I'll try writing a webserver that implements hot-reloading of HTML(+CSS, +Javascript) in the browser. Edit the local file and ...
[Corion]: ... the browser(s) get a ping to a) refresh the page or b) reload "just" the changed parts, keeping the scroll position etc.
[Corion]: But I also have to look at how I can make WWW::Mechanize:: RemoteBrowser a reality, and how to make it safe from malicious content ;)
[Corion]: Part of wanting hot-reloading is that I think I've stumbled on a very simple set of CSS that I maybe want to use for a blog, but I want to try that out on mobile too, and I also want to add/modify it slightly so it has a header too...
[Corion]: ... and having hot reloading would make it easy to view the changes in multiple browser windows of different sizes, and on Android, simultaneously

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