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Re: opening a file destroys nulling entries in a list?!?!

by l2kashe (Deacon)
on Aug 07, 2003 at 03:39 UTC ( #281730=note: print w/ replies, xml ) Need Help??


in reply to opening a file destroys nulling entries in a list?!?!

and now for something entirely different..

just as an aside, using map in a void context (i.e. not returning anything), is generally considered a BadThing(TM). If you are simply looking for a way to do simple single line loops, you can always use for().. ala

print "before: $_\n" for @instances; screwed "$_" for @instances; print "after: $_\n" for @instances;

You might already know this, you might not, but I figured I would toss it out there. The reason it't not so good, is Perl can go through a lot of trouble to build a list of things to return from the map block, and if you don't use them its simply a waste of processor time and memory that could be better spent doing other things.

use perl;


Comment on Re: opening a file destroys nulling entries in a list?!?!
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Re: Re: opening a file destroys nulling entries in a list?!?!
by matpalm (Initiate) on Aug 07, 2003 at 03:47 UTC
    my first attempt was with
    foreach(@instances) { screwed "$_"; };
    and then when it didn't work i showed it to someone here at work and he introduced me to maps so i used
    map { screwed "$_"; } @instances;
    but...
    screwed "$_" for @instances;
    ..is even less typing again!

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