NetNews Usenet Archive 1993 #3/NN_1993_3.iso/spool/comp/lang/perl/7930

Text File | 1993-01-21 | 1.5 KB | 64 lines

Newsgroups: comp.lang.perl
Path: sparky!uunet!srvr1.engin.umich.edu!uvaarpa!mmdf
From: Alan Stebbens <[e-mail]>
Subject: Re: lists in associative arrays
Message-ID: <[e-mail]>
Sender: [e-mail] (Mail System)
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Organization: The Internet
Date: Thu, 21 Jan 1993 17:33:18 GMT
Lines: 52

| From: [e-mail] (Daniel Quinlan)
| ...I think there must be some better way to do this
| than ...
|     $list{$i} = "$list{$i} new_entry" ;

| From:    Tom Christiansen <[e-mail]>
| The ".=" operator would be a bit more efficient, I suspect.

The way I build lists is:

    $list .= $new.' ';

Then, when you're done, I either use

    @items = split(' ',$list);

to ignore the trailing blanks when separating items, or to simply remove
the trailing blank:

    chop($list);

If you are building an array of accumulating lists:

    while (<>) {
        ...
        $list[$index] .= $new.' ';
        ...
    }

You choose to either ignore the trailing blanks, or chop them:

    grep(chop,@list);


If you are building a associative array of accumulating lists:

    while (<>) {
        ...
        $list{$entry} .= $new.' ';
        ...
    }

Simiarly, you can ignore the trailing blanks, chop them, or use split
(as Tom pointed out above) to ignore them.

    foreach $ent (keys %list) {
        chop($list{$ent});
        }

-- Alan Stebbens, UCSB, Santa Barbara <[e-mail]>
"If all you have is a hammer, then everything looks like a nail."