Re: Problem generating a hashtable

This (basically exact same as yours) code works for me (prints "k1\nk2\n") -- what is a sample of your <FILE>?:

use strict;
use warnings;
my %hash = map {
     (split /:/, $_ )[0] => (split /:/, $_ )[2]
    } <DATA>;
print join ( "\n", sort keys %hash ) . "\n";
__DATA__
k1:asd:v1
k2:asd:v2
[download]

One suggestion though, would be to change the map so that the split() is only done once (no functionality change, just for efficiency):

  map {
    my @tmp = split /:/, $_;
    $tmp[0] => $tmp[2];
  } <FILE>
[download]

(could also do map { (split(/:/, $_)) [0,2] } but that's not as clear that it's key/value pairs)
Update: Oops. I see now that OP said he won't be using the two splits....

Comment on Re: Problem generating a hashtable Select or Download Code

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Re^2: Problem generating a hashtable by techra (Pilgrim) on May 13, 2005 at 14:36 UTC
I only wish everyone who used map in their code would do so as beautifully as you did in your 2nd example. Multiple lines! Named variables! I can understand at a glance exactly what this does. Map has been a learning hurdle for me in all my years of Perl Development, mostly because nearly all examples of it I see obfuscate its actual function. Thank you for this good example.	[reply]
Re^2: Problem generating a hashtable by Tomtom (Scribe) on May 13, 2005 at 13:34 UTC
Actually, I changed it to `my ( $key, $value ) = map { (split(/:/, $_)) [0,2] } <FILE>;` [download] :) In fact, `(split /:/, $_ )[0] => (split /:/, $_ )[2]` [download] does work a first time on another tab, but seems to invert the keys and the values the second time :/	[reply] [d/l] [select]
Re^2: Problem generating a hashtable by blazar (Canon) on Jul 19, 2005 at 14:23 UTC
could also do `map { (split(/:/, $_)) [0,2] }` but that's not as clear that it's key/value pairs This is indeed a good point, but if you're not too much concerned about it, then `my %hash=map +(split /:/)[0,2], <DATA>;` [download] would be shorter and clearer, IMHO. In particular a very nice point about `$_` is that it is the "topicalizer" so that it's the default implicit argument of just so many "actions"...	[reply] [d/l] [select]