[prev in list] [next in list] [prev in thread] [next in thread] 

List:       ruby-talk
Subject:    Re: Why nil
From:       Tanguy Andreani <breakfast () cock ! li>
Date:       2018-07-04 12:26:19
Message-ID: ffc59fd3-2033-4c1a-84b4-81f28a6eea5f () email ! android ! com
[Download RAW message or body]

[Attachment #2 (text/html)]

<div dir='auto'>You forgot to use `@` so `a` is interpreted as a local variable which \
in this case has no value yet.</div><div class="gmail_extra"><br><div \
class="gmail_quote">Le 4 juil. 2018 14:06, dade &lt;dimapg@rambler.ru&gt; a écrit \
:<br type="attribution" /><blockquote class="quote" style="margin:0 0 0 \
.8ex;border-left:1px #ccc solid;padding-left:1ex"><div>Hello, let&#39;s look at an \
example<br /></div><div><br /></div><div>class A<br /></div><div>  attr_accessor \
:a<br /></div><div><br /></div><div>  def initialize(a)<br /></div><div>    &#64;a \
&#61; a<br /></div><div>  end<br /></div><div><br /></div><div>  def method1(val)<br \
/></div><div>    a &#61; val<br /></div><div>  end<br /></div><div><br /></div><div>  \
def method2(val)<br /></div><div>    a &#61; a &#43; val<br /></div><div>  end<br \
/></div><div>end<br /></div><div><br /></div><div>a &#61; A.new(1)<br \
/></div><div>a.method1(2) #&#61;&gt; 3<br /></div><div>a.method2(2) #&#61;&gt; \
undefined method &#96;&#43;&#39; for nil:NilClass<br /></div><div><br \
/></div><div>Why the second a is nil?<br /></div><div><br /></div><div><br \
/></div><div><br /></div><div>dade.</div><div><br \
/></div></blockquote></div><br></div>



Unsubscribe: <mailto:ruby-talk-request@ruby-lang.org?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-talk>


[prev in list] [next in list] [prev in thread] [next in thread]