Re: Printing an array in columns

#!/usr/bin/perl

use strict;
use warnings 'all';

my @array = qw/one two three four five six seven eight nine ten/;
my $cols  = 3;

my $max   = -1;

$_ > $max && ($max = $_) for map {length} @array;

while (@array) {
    print join " " => map {sprintf "%-${max}s" => $_}
                           splice @array => 0, $cols;
    print "\n";
}
[download]

Abigail

Comment on Re: Printing an array in columns - improvements? Download Code

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Re: Re: Printing an array in columns - improvements? by BrowserUk (Patriarch) on Jul 18, 2002 at 16:57 UTC
Could I prevail upon you (or anyone) to explain the three uses of the `=>` operator in your answer? I seen this a few times now, and have tried to understand it, but have to admit that I am completely foxed by it. Thanks.	[reply] [d/l]
Re: Re: Re: Printing an array in columns - improvements? by demerphq (Chancellor) on Jul 18, 2002 at 18:20 UTC
Well, its not from the horses mouth, but heres a quick explanation. Basically all Abigail-II is doing is conceptually breaking up the code by using the fat comma. Dont forget that semantically the => is equivelent to a comma (,) with the added nicety that if the item on the lhs is a bareword the bareword is automatically quoted. `print join " " => map {sprintf "%-${max}s" => $_} splice @array => 0, $cols;` [download] is the same thing as `print join " " , map {sprintf "%-${max}s", $_} splice @array, 0, $cols;` [download] as well as `print join(" ",map {sprintf "%-${max}s",$_}splice(@array,0,$cols));` [download] The easiest to read is the first I think you'll agree. (although i dont know that i would have used a fat comma in the sprintf() call but whatever ;-) Yves / DeMerphq --- Writing a good benchmark isnt as easy as it might look.	[reply] [d/l] [select]