Re: can't use certain hashnames when traversing a slightly complex hash

[Athanasius]

Works OK for me:

#! perl
use strict;
use warnings;

my @gists = (
                {
                    files =>
                    {
                        'main.html' => 
                        {
                            language => 'HTML',
                            filename => 'main.html',
                            type     => 'text/html',
                            size     =>  713,
                            raw_url  => 'THIS IS WHAT I WANT'
                        }
                    }
                }
            );

foreach my $g (@gists)
{
    my @files = keys(%{$g->{files}});
    my $file  = $files[0];

    print $g->{files}->{$file}->{raw_url};
}

Output:

21:28 >perl 472_SoPW.pl
THIS IS WHAT I WANT
21:28 >

The only difference a dot in the hash key makes is that the key has to be quoted under use strict.

Can you provide a minimal example that demonstrates the problem you are seeing?

[NetWallah]

Inside the loop, try this

foreach my $g (@gists)
{
    for my $filename( keys(%{$g->{files}}) )
    {
        my $fref = $g->{files}{$filename}; # Simplify access to conten
+ts ..( -> is optional betweeen "}{" )
        print $fref->{raw_url};
        last; # If you only want info for ONE file
    }
}

[gideondsouza]

Bah! This is so ridiculous, I retyped the code when I was posting the question and ended up typing the code correctly!!

The code was originally like this:

print ->$g->{files}->{$file}->{raw_url};

How do you usually figure the code for a hash traversal? I kept having to restart my webapp, Do you usually use the debugger and inspect the hash? I guess I really have to get used to the command line debugger

Thanks so much for your replies dear monks! Sorry about the trouble! This is another pretty silly issue.

[Athanasius]

How do you usually figure the code for a hash traversal?

Not sure what you’re asking here, but for the record, the line:

print $g->{files}->{$file}->{raw_url};

can be simplified to:

print $g->{files}{$file}{raw_url};

because “The arrow is optional between brackets subscripts” (perlref#Using-References, point 3).

Do you usually use the debugger and inspect the hash?

No, I’d likely use Data::Dump or Data::Dumper, as in the OP.

Anyway, glad the problem has been sorted. :-)

[gideondsouza]

I ended up with that syntax issue just because I kept switching between the code and the browser and the killing/starting the server. Wondered if there was a faster way

Anyway, it's just been less than two months since I met perl, I'll get used to Data::Dumper :)