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

I have the following arrays with different lengths that I want to map them with the same key. 
# Week numbers, 8 columns
@headers = ("2011-34", "2011-35", "2011-36", "2011-37", "2011-38", "20
+11-39", "2011-40", "2011-41");

%data = ("2011-34", BCE,
         "2011-35", YZA,
         "2011-36", MID,
         "2011-37", KAL,
         "2011-39", WUL,
         "2011-41", YOK);

# Need to map output as below:
|    |2011-34|2011-35|2011-36|2011-37|2011-38|2011-39|2011-40|2011-41|
| 1 |  BCE  |  YZA   |   MID  |  KAL   |            |  WUL |          
+  |  YOK  |

[download]
Can someone here help? Thanks in adance !

Replies are listed 'Best First'.
Re: Need Help Mapping Arrays
by Eliya (Vicar) on Aug 23, 2011 at 15:47 UTC
    I have the following arrays with different lengths

    Actually, you have one array and a hash. This means you can do a simple lookup for each element of the array (i.e. $data{$element} ).

    The following snippet would, for example, produce the output you want: 

    # ... data declarations as you have it (but with values "BCE" etc. quo
+ted)

print "|   |", (map sprintf(" %8s |", $_),            @headers), "\n";
+  # print column headers
print "| 1 |", (map sprintf(" %8s |", $data{$_}||""), @headers), "\n";
+  # print row of data

__END__
|   |  2011-34 |  2011-35 |  2011-36 |  2011-37 |  2011-38 |  2011-39 
+|  2011-40 |  2011-41 |
| 1 |      BCE |      YZA |      MID |      KAL |          |      WUL 
+|          |      YOK |

    [download]

    P.S. please put <c> ... </c> around code sections of your post. This makes it easier to read.

[reply]
[d/l]
[select]
      Couldn't you dump the header array altogether and just load a single hash? You could sort the keys, if you needed the order fixed. (or use Tie::IxHash for key ordering)
[reply]
Re: Need Help Mapping Arrays
by locked_user sundialsvc4 (Abbot) on Aug 24, 2011 at 12:49 UTC

    I would use an array of hashrefs, because you know you’re going to have a certain number of rows whether those rows are empty or filled.

    Another trick is to capture the column-headings as you encounter them.   A hash is very handy for this.   If you simply do $$keys_encountered{$heading} = 1; along the way, you can use sort keys(%$keys_encountered) to read all of the column headings you actually encountered, in alphabetic order.   (In this case, the value of the hash entry is unimportant; you care about the presence of the key.)

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