You don't really push to a hash, you can - but push is usually reserved for array (and yes, a hash is an array). My point is that you assign a value to a hash key - that value can be a scalar (the value), a reference (the pointer), or other things.

Here is an example that reads 'configuration info' from Perl's built in DATA filehandle. I use DATA because it's easy and you only need one file for demonstrations. Anyhow, the configuration is simply two values seperated by a comma per line. The while loop processes DATA one line at a time and creates a new struct object with the values it finds. After the struct is instantiated, it is pushed to an array. Since it is already a reference there is no need to de-reference it. The last line is a for loop that prints out only one of the attributes for each struct in the array.

use strict; use Class::Struct; # declare the struct struct(MyStruct => { even => '$', odd => '$', }); # create array of structs my @structs; while (my $line = <DATA>) { chomp $line; my ($odd,$even) = split(',',$line); my $obj = new MyStruct; $obj->odd($odd); $obj->even($even); push(@structs,$obj); } print $_->odd(), "\n" foreach (@structs); __DATA__ one,two three,four five,six seven,eight nine,ten
But hold it right there! Why are you using Class:Struct? No offense to the author, but if you are going to code in Perl, code like Perl. Check this out:
use strict; # create array of structs my @structs; while (my $line = <DATA>) { chomp $line; my ($odd,$even) = split(',',$line); my %hash = ( odd => $odd, even => $even, ); # i do have to de-reference %hash though push(@structs,\%hash); } print $_->{'odd'}, "\n" foreach (@structs); __DATA__ one,two three,four five,six seven,eight nine,ten
Same thing with less lines, and i spared using map to golf it down even further ... oh what the hell:
print $_->{odd},"\n"for map{my($o,$e)=split',',$_;{odd=>$o,even=>$e}}< +DATA>;
Welcome to Perl. :)

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
F--F--F--F--F--F--F--F--
(the triplet paradiddle)

In reply to (jeffa) 3Re: Dynamically allocating variables by jeffa
in thread Dynamically allocating variables by newatperl

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



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.