title: Ruby methods equivalent of "if a in list" in python?
body: <p>In python I can use this to check if the element in list <code>a</code>:</p>
  
  <pre><code>&gt;&gt;&gt; a = range(10)
  &gt;&gt;&gt; 5 in a
  True
  &gt;&gt;&gt; 16 in a
  False
  </code></pre>
  
  <p>How this can be done in Ruby?</p>