Problems with Hash Keys and Spaces

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

Hi everyone,
I am trying to pull the value of a hash key that has spaces. First off, let me show you the code and then I will ask my question.

my %hash = (
  "Common SW Component" => "4885",
  "Test MMA" => "5130",
  "Generic key" => "5033",
  "Another generic key" => "4575",
);
print "$hash{$variable}\n";
[download]

Now, say $variable contains a hash key. If the hash key contains a space I get this error, "Use of uninitialized value in concatenation (.) or string" However, if I were to type in print "$hash{'key with space'}\n"; the value gets returned. Is it possible to have the value returned with the $variable having spaces? I hope this makes sense. Thanks in advance.

Comment on Problems with Hash Keys and Spaces Select or Download Code

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Re: Problems with Hash Keys and Spaces by kyle (Abbot) on Aug 08, 2008 at 16:27 UTC
Works fine for me. Are you sure `$variable` has in it what you think it has in it? Where are you getting the value? Have you tried to print it or dump it with Data::Dumper? `my %hash = ( "Common SW Component" => "4885", "Test MMA" => "5130", "Generic key" => "5033", "Another generic key" => "4575", ); my $variable = "Another generic key"; print "$hash{$variable} ($variable)\n"; __END__ 4575 (Another generic key)` [download]	[reply] [d/l] [select]
Re^2: Problems with Hash Keys and Spaces by Anonymous Monk on Aug 08, 2008 at 16:31 UTC
Yes, the variable is actually being pulled from an array slot (number 1) and then matched against the key to return the numerical value. If I print the `$array[1]` it returns exactly what the key should be, but when i plug it into the previous code I posted I get the error.	[reply] [d/l]
Re^3: Problems with Hash Keys and Spaces by kyle (Abbot) on Aug 08, 2008 at 16:32 UTC
Perhaps you could show us some more of the code you're using. The code you've posted so far doesn't show the problem.	[reply]
Re: Problems with Hash Keys and Spaces by tptass (Sexton) on Aug 08, 2008 at 16:29 UTC
How are you defining $variable? I just ran your code with $variable set to "Another generic key" and received 4575 out. See code below: `my %hash = ( "Common SW Component" => "4885", "Test MMA" => "5130", "Generic key" => "5033", "Another generic key" => "4575", ); my $variable = "Another generic key"; print "$hash{$variable}\n";` [download]	[reply] [d/l]
Re^2: Problems with Hash Keys and Spaces by Anonymous Monk on Aug 08, 2008 at 16:33 UTC
`my $variable = "$temp[1]";`	[reply] [d/l]
Re^3: Problems with Hash Keys and Spaces by FunkyMonk (Bishop) on Aug 08, 2008 at 16:36 UTC
So, What's in `$temp[1]`? Add `use Data::Dumper;` [download] Near the top of your program, and `print Dumper \@temp;` [download] just before the line with the error Unless I state otherwise, all my code runs with strict and warnings	[reply] [d/l] [select]
Re^4: Problems with Hash Keys and Spaces by Anonymous Monk on Aug 08, 2008 at 16:43 UTC
Re^5: Problems with Hash Keys and Spaces by FunkyMonk (Bishop) on Aug 08, 2008 at 16:46 UTC
Some notes below your chosen depth have not been shown here
Re^5: Problems with Hash Keys and Spaces by tptass (Sexton) on Aug 08, 2008 at 17:04 UTC
Re^5: Problems with Hash Keys and Spaces by Your Mother (Archbishop) on Aug 08, 2008 at 22:48 UTC
Re^5: Problems with Hash Keys and Spaces by varian (Chaplain) on Aug 09, 2008 at 12:42 UTC
Re^4: Problems with Hash Keys and Spaces by Anonymous Monk on Aug 08, 2008 at 16:46 UTC
Re^3: Problems with Hash Keys and Spaces by repellent (Priest) on Aug 08, 2008 at 17:38 UTC
Don't interpolate `"$temp[1]"`. You may be losing information due to interpolation. Try this instead: `my $variable = $temp[1];` [download]	[reply] [d/l] [select]