Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl Monk, Perl Meditation
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??
So, I've read over explanations on making a hash of arrays and attempted to adopt the methods into a program to take a simple datafile and turn it into a hash of arrays. The file has the format
1,2 1,3 1,4 2,3 2,5 2,5
And I want to make a hash of arrays where the first column is the key and the second column is the data. I've done it like so:
local %DATAHASH; open (DATA, 'foo.csv'); while (<DATA>){ chomp; my @datarow=split(/,/, $_); push(@{$DATAHASH{$datarow[0]}}, ($datarow[1])); }
And yet, whenever I try and print out the contents of DATAHASH, either after the while loop or in its midst using Dumper($DATAHASH}, I get a $VAR1 = undef Any advice on remedying this situation? And looking further down the line, for something that will have two seperate keys (e.g. 1,2,3 is a line from the file) I'm using push( @{$DATAHASH{$datarow[0]}->{$datarow[1]}}, ($datarow[2]) );, which I'm assuming I'll just modify in the same way.

In reply to Making a hash of arrays from a datafile by redbeard

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others goofing around in the Monastery: (7)
As of 2024-04-18 03:07 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found