user defined variable as hash key index

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

Hi all! Can someone tell me why this doesn't work?

#!/usr/bin/perl
use warnings;
use strict;

my %numbers=(
nameA => "1234567",
nameB => "2234567",
nameC => "3234567",
nameD => "4234567",
nameE => "5234567"
);

print "Who's number are you looking for? : \n";
my $who = <STDIN>;

print "$who number is $numbers{$who}\n";
[download]

this is the output i get:

C:\BegPerl\chap3\Exercises>chap3_ex3.pl
Who's number are you looking for? :
"nameA"
Use of uninitialized value in concatenation (.) or string at
C:\BegPerl\chap3\Exercises\chap3_ex3.pl line 21,
<STDIN> li
ne 1.
nameA
number is
[download]

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Re: user defined variable as hash key index by FunkyMonk (Bishop) on Oct 15, 2007 at 21:27 UTC
You need to chomp your input to get rid of the newline: `print "Who's number are you looking for? : \n"; my $who = <STDIN>; chomp $who; print "$who number is $numbers{$who}\n";` [download] Code look much better if you wrap it in `<code> ... </code>` tags :-)	[reply] [d/l] [select]
Re^2: user defined variable as hash key index by pleasehelp (Initiate) on Oct 15, 2007 at 21:54 UTC
THANKS dude! The book i'm learning from has yet to introduce chomp so i don't really know what they expected.	[reply]
Re: user defined variable as hash key index by naikonta (Curate) on Oct 16, 2007 at 01:12 UTC
Additionally from FunkyMonk's answer, you may also want to put some checking to see if supplied name doesn't exist in `%numbers` to avoid unitialized warning. `print "Who's number are you looking for? : \n"; chomp(my $who = <STDIN>); my $number = $numbers{$who} \|\| 'unknown'; print "$who number is $number\n";` [download] Open source softwares? Share and enjoy. Make profit from them if you can. Yet, share and enjoy!	[reply] [d/l] [select]