[Linux-disciples] Converting an array to a hash

[Chung-chieh Shan]

On 2004-10-06T13:11:36-0400, Adam Rosi-Kessel wrote:
> I doubt you'd be able to measure a performance difference between any of
> the various ways of accomplishing this.

Yeah.

> Still, if you really want to
> skip the array, this should work:
> 
> my %wordsHash;
> while (<>) {
>   foreach my $word (m/([A-Za-z]+)/g) {
>     $wordsHash{$word} = defined;
>   }
> }

You can assign multiple entries into a hash at the same time:

    @hash{1,2,3} = (4,5,6);

If the right-hand-side list is shorter than the left-hand-side, then
undef is used.  Hence you can make a hash whose keys are words and
values are undef:

    my %wordsHash;
    @wordsHash{m/([A-Za-z]+)/g} = () while <>;

(Untested code.)

-- 
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