Re: What's up with the double dollar sign? ($$)

From: Chris Hope (chris_at_electrictoolbox.com)
Date: 04/27/04 

Date: Wed, 28 Apr 2004 08:15:34 +1200

ScareCrowe wrote:
> I think it has something to do with globals, but what exactly is the
> purpose of the '$$' with variables?
> I mean what's the difference between '$var' and '$$var'?
> When would be the appropriate time to use '$$' instead of '$'?

$foo = 'bar';
$bar = 'xyz';
$zoo = 'abc';

print $foo . "\n";
print $bar . "\n";
print $$foo . "\n";

This will print out
        bar
        xyz
        xyz

$$foo is evaluated as $bar because the value of $foo is 'bar'. If $foo was
changed to $foo = 'zoo' then print $$foo would now print 'abc'

The purpose of doing so? I find it often obfuscates code but I'm sure there
must be some useful purpose for it sometimes.

Hope this all makes sense... 

-- 
Chris Hope
The Electric Toolbox - http://www.electrictoolbox.com/

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