Re: Hash slice to get DB values - include undefined values?

This already happens as the code below shows:

my %hash=(a=>1,b=>2,c=>3);
my @list=@hash{qw(a b c d e f)};
print "\t$_:",defined $list[$_] ? $list[$_] : "undef" foreach 0..$#lis
+t;
__END__
    0:1    1:2    2:3    3:undef    4:undef    5:undef
[download]

Undef is returned as with any hash lookup where the key is undefined. BTW I wrote a module called Tie::Hash::Trie (which I have yet to upload anywhere, life got in the way :-) which amongst other things alows this to be changed to any arbitrary value. Let me know if you want to see.

Yves / DeMerphq
--
This space for rent.

Comment on Re: Hash slice to get DB values - include undefined values? Download Code

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Re: Re: Hash slice to get DB values - include undefined values? by George_Sherston (Vicar) on Dec 11, 2001 at 19:55 UTC
Duh - how right you are... I thought that my problem was happening because my `@vals` array was too short... but, armed with the certainty that it couldn't be that, I revisit the code and find that it's another problem. The moral of this story is, if you want to know what's in an array in your CGI, don't do `print @array;` [download] do `print $_,br for @array;` [download] Thanks! § George Sherston	[reply] [d/l] [select]
Re: Re: Re: Hash slice to get DB values - include undefined values? by demerphq (Chancellor) on Dec 11, 2001 at 20:00 UTC
Or perhaps `print join("<BR>",@array)."<BR>";` [download] BTW, im sure you know this already but you could convert all of the undefs to a given constant quite easily `my @values=map { exists $hash{$_} ? $hash{$_} : $constant } @keys_need +ed;` [download] You might want to change the exists() to a defined() if you dont want _any_ undefs getting through. :-) Yves / DeMerphq -- This space for rent.	[reply] [d/l] [select]