From: Dane Harrigan <dane.harrigan@...>
Date: 2011-10-23T08:33:46+09:00
Subject: Re: global variable -- last expression

Eric is right. IRB just sets _ as a variable.

In "irb/context.rb" you'll find:

162:    def set_last_value(value)
163:      @last_value = value
164:      @workspace.evaluate self, "_ = IRB.CurrentContext.last_value"
165:    end

Take a look at line 164, _ is set right there.



-Dane



On Fri, Oct 21, 2011 at 8:05 PM, Eric Hodel <drbrain@segment7.net> wrote:
> On Oct 21, 2011, at 7:46 PM, Chad Perrin wrote:
>> On Sat, Oct 22, 2011 at 10:48:00AM +0900, Eric Hodel wrote:
>>> On Oct 21, 2011, at 5:34 PM, basha c. wrote:
>>>> In IRB the last expression is in _ . But if you  are in a ruby program
>>>> how to get the last expression.
>>>
>>> You assign it to a variable:
>>>
>>> value = 1 + 1
>>>
>>> puts "the value was #{value}"
>>
>> Mightn't that lead to some "shallow copy" problems in some cases?
>
> No more than in IRB.
>
>