no uninitialized warnings

si_lence has asked for the wisdom of the Perl Monks concerning the following question:

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Re: no uninitialized warnings by herveus (Prior) on Aug 25, 2004 at 13:06 UTC
Howdy! What do you want displayed when the variable is uninitialized? Your approach is straightforward and clear. Data::Dumper provides another mechanism that will show uninitialized values as "undef" without requiring you to write lots of code. yours, Michael	[reply]
Re: no uninitialized warnings by ccn (Vicar) on Aug 25, 2004 at 12:46 UTC
Why don't you just initialize them? `$_ \|\|= '' for $var1, $var2, $var3; print "var1=$var1 -- var2=$var2 -- var3=$var3\n";` [download] or `print "var1=", $var1 \|\| '', " -- var2=", $var2 \|\| '', " -- var3=", $va +r3 \|\| '', "\n";` [download]	[reply] [d/l] [select]
Re^2: no uninitialized warnings by busunsl (Vicar) on Aug 25, 2004 at 12:54 UTC
Danger, Will Robinson. Danger! If `$var1` has the value `0`, it will be set to `''`, which might not be what you want.	[reply]
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 $_? $_: '[__UNDEF__]' for @x ; print "@x" ;` [download] Ciao! `--bronto` The very nature of Perl to be like natural language--inconsistant and full of dwim and special cases--makes it impossible to know it all without simply memorizing the documentation (which is not complete or totally correct anyway). --John M. Dlugosz	[reply] [d/l]
Re^4: no uninitialized warnings by ccn (Vicar) on Aug 25, 2004 at 16:46 UTC
Re^5: no uninitialized warnings by Aristotle (Chancellor) on Aug 29, 2004 at 19:25 UTC
Re^2: no uninitialized warnings by revdiablo (Prior) on Aug 25, 2004 at 17:29 UTC
If the values might be uninitialized in the normal course of operation, and it's acceptible, then I see no problem just turning off the warning, as the OP has done. This is Perl, after all. The language should do what we want, not the other way around. :-)	[reply]
Re: no uninitialized warnings by Forsaken (Friar) on Aug 26, 2004 at 09:56 UTC
well, i'm one of those people that considers warnings blasphemy, so i avoid them like the plague. In a case like this I'd simply use something like: print "some sort of introduction of the following comes here"; if($var1) { print "\$var1 = $var1 "; } if($var2) { print "\$var2 = $var2 "; } if($var3) { print "\$var3 = $var3"; } print "\n"; perhaps i'm allowing the quirks of the language to dominate my style here, but I have all my bases covered this way :-) Additionally, I tend to encapsulate a construction like this in a if($debug) {} so as to allow me to turn all the debug messages in a script on or off with the change of a single variable somewhere.	[reply]
Re: no uninitialized warnings by si_lence (Deacon) on Aug 26, 2004 at 12:29 UTC
Thanks for all the input! I used Data::Dumper to print out larger data structures, but using it to print out the names is very nice too. `print Data::Dumper->Dump([$var1, $var2, $var3], [qw($var1 $var2 $v +ar3)]);` [download] Speaking of a $debug switch to print out information only while debugging: I usually use an if statement modifier so I can use more than one level of verbosity `my $v=0; #0 for silent, 1 for main info, 2 for all info ... print "something important\n" if $v > 0; print "something not so important\n" if $v >1;` [download] si_lence	[reply] [d/l] [select]


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