From: BlueFox <blue_fox@...>
Date: 2006-02-24T15:48:32+09:00
Subject: Re: What's mean? global variables


> Jacob Fugal wrote:
>> $test is a global variable. Thats important in this case for scope --
>> $test continues to exist and retain its value between invocations of
>> test. The ||= idiom is one commonly found in ruby. It's similar to +=
>> in that it is simply short hand for "$test = $test || Test.new". $test
>> starts with a value of nil, and the first time test is run (unless you
>> manually set $test beforehand), $test is initialized to a new instance
>> of Test, since "(nil || anything) == anything". On subsequent runs,
>> $test retains its value. From this behavior, ||= can be thought of as
>> a "default initializer" operator.
>
> Jacob,
>
> So is this a shortcut for creating a singleton in Ruby? Albeit a slightly 
> different one I would guess, using a global variable to store a single 
> instance rather than using a class method to instantiate a new or return 
> the existing instance.
>
> Thanks...
> -dave
>
>

Oh! the test function just an another way to access the global variable 
$test?

yesterday i forgot  that we can define a fuction outside classes(unlike 
java) and function's return value is the last statement's return value?



Thanks very much.



leo.