[LRUG] Ruby question for a change! Why does this happen...

[Gabe da Silveira]

If you're right your example doesn't show it because you set the local var
`foo` to ["b"] before you add ["c"] to it.


On Tue, Jul 1, 2014 at 10:52 AM, Ronny Ager-Wick <ronny at ager-wick.com>
wrote:

>  I was just playing around in irb, and it seems to work... I didn't look
> into it theoretically, but when the map and the terrain don't match, I tend
> to trust the terrain.
>
>
> irb(main):001:0> def foo
> irb(main):002:1>   @bar ||= []
> irb(main):003:1> end
> => nil
> irb(main):004:0> def foo= obj
> irb(main):005:1>   @bar = obj
> irb(main):006:1> end
> => nil
> irb(main):007:0> foo
> => []
> irb(main):008:0> foo + ["a"]
> => ["a"]
> irb(main):009:0> foo = ["b"]
> => ["b"]
> irb(main):010:0> foo += ["c"]
> => ["b", "c"]
>
>
>
> On 01/07/14 17:46, Gabe da Silveira wrote:
>
> That will do absolutely nothing since he's not calling self.foo=
>
>
> On Tue, Jul 1, 2014 at 10:36 AM, Ronny Ager-Wick <ronny at ager-wick.com>
> wrote:
>
>>  You don't have any definition for what should happen to foo when
>> assigning a value.
>> Try adding this:
>>
>> def foo= obj
>>   @b = obj
>> end
>>
>>
>>
>> On 01/07/14 17:12, Kenneth Lee wrote:
>>
>>   Doing some lazy instantiation and come across this oddity, maybe I'm
>> just being dense.
>>
>> $ irb
>>
>> irb(main):001:0> def foo
>>
>> irb(main):002:1>   @bar ||= []
>>
>> irb(main):003:1> end
>>
>> => :foo
>>
>> irb(main):004:0> foo
>>
>> => []
>>
>> irb(main):005:0> foo += []
>>
>> NoMethodError: undefined method `+' for nil:NilClass
>>
>> from (irb):5
>>
>> from /Users/ken/.rbenv/versions/2.1.1/bin/irb:11:in `<main>'
>>
>> irb(main):006:0> foo
>>
>> => nil
>>
>>
>>   _______________________________________________
>> Chat mailing listChat at lists.lrug.orghttp://lists.lrug.org/listinfo.cgi/chat-lrug.org
>>
>>
>>
>> _______________________________________________
>> Chat mailing list
>> Chat at lists.lrug.org
>> http://lists.lrug.org/listinfo.cgi/chat-lrug.org
>>
>>
>
>
> _______________________________________________
> Chat mailing listChat at lists.lrug.orghttp://lists.lrug.org/listinfo.cgi/chat-lrug.org
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.lrug.org/pipermail/chat-lrug.org/attachments/20140701/158ec92b/attachment-0003.html>