https://ruby-china.org/idotjkl en-us <p>这是 Ruby Programming 第十一章的一个练习，讲的是如何在不新建数组的情况下，取出 3 的倍数。程序如下，但发现 list.delete 总不能如期删除 非 3 的倍数。</p> <pre class="highlight ruby"><code><span class="n">list</span> <span class="o">=</span> <span class="p">[]</span> <span class="k">for</span> <span class="n">i</span> <span class="k">in</span> <span class="mi">0</span><span class="o">...</span><span class="mi">100</span> <span class="n">list</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="o">=</span><span class="n">i</span><span class="o">+</span><span class="mi">1</span><span class="p">;</span> <span class="k">end</span> <span class="n">list</span><span class="p">.</span><span class="nf">each</span><span class="p">{</span><span class="o">|</span><span class="n">i</span><span class="o">|</span> <span class="k">if</span> <span class="p">((</span><span class="n">i</span> <span class="o">%</span> <span class="mi">3</span><span class="p">)</span> <span class="o">!=</span> <span class="mi">0</span><span class="p">)</span> <span class="k">then</span> <span class="n">list</span><span class="p">.</span><span class="nf">delete</span><span class="p">(</span><span class="n">i</span><span class="p">)</span> <span class="k">end</span> <span class="p">}</span> <span class="nb">p</span> <span class="n">list</span> </code></pre> idotjkl Thu, 29 Mar 2012 21:57:46 +0800 https://ruby-china.org/topics/2253 https://ruby-china.org/topics/2253