Wrong hash accessing?

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

Hello!

When i try access to hash with $name i get error:

Use of uninitialized value within %p in concatenation (.) or string at ./7.plx line 15, <STDIN> line 1.

#!/usr/bin/perl

use warnings;
use strict;
use 5.010;

my %p = ( 
    "Word1" => "WordWord1",
    "Word2" => "WordWord2",
    "Word3" => "WordWord3",
);

while(<STDIN>) {
    my $name = $_;
    print "$p{$name}\n";
}
[download]

What is wrong with my code?

Comment on Wrong hash accessing? Download Code

Replies are listed 'Best First'.
Re: Wrong hash accessing? by davido (Cardinal) on Mar 18, 2015 at 05:10 UTC
You need to chomp your input. When the user types "`Word1`" and then hits `<ENTER>`, that `<ENTER>` gets included in the input string as a "newline" ("`\n`"). So the input string looks like "`Word1\n`". There is no hash key named "`Word1\n`", only "`Word1`". Or to put it another way, "`Word1\n`" and "`Word1`" would be two different keys. This will work as you seem to intend: `while(<STDIN>) { chomp $_; # Remove the trailing newline from the contents of $_. my $name = $_; print "$p{$name}\n"; }` [download] Dave	[reply] [d/l] [select]
Re^2: Wrong hash accessing? by Firsov (Novice) on Mar 18, 2015 at 05:34 UTC
It is seems to be work. Thank you very much!	[reply]