Re: A way to avoid repeated conditional loops

in reply to A way to avoid repeated conditional loops

Use m?alpha? instead of m/alpha/ to match only once:

#!/usr/bin/perl

use warnings;
use strict;

while (<DATA>) {
    if (m?alpha?) {
        print "+ $_";
    } else {
        print "- $_";
    }
}

__DATA__
beta
beta
alpha
beta
beta
alpha
alpha
beta
[download]

Results in:

- beta
- beta
+ alpha
- beta
- beta
- alpha
- alpha
- beta
[download]

Comment on Re: A way to avoid repeated conditional loops Select or Download Code

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Re^2: A way to avoid repeated conditional loops by Deus Ex (Scribe) on Aug 25, 2011 at 13:13 UTC
It would be a nice trick, but the match is just ignored after the first time, so the conditions keeps getting evaluated. Thanks though	[reply]
Re^3: A way to avoid repeated conditional loops by pvaldes (Chaplain) on Aug 26, 2011 at 00:45 UTC
`=~ s/^alpha/^#alpha/` ... and now do what you want with the whole file	[reply] [d/l]

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