title: NULL type of object in R
body: <p>I am still a novice user in R, and have been reading Advanced R by Hadley to improve my R programming skills.</p>
  
  <p>I came across this code in his book:</p>
  
  <pre><code>NULL&gt;0 
  </code></pre>
  
  <p>The output for this code is <code>logical(0)</code>. </p>
  
  <p>I have two questions on this:</p>
  
  <p><strong>Question 1</strong>: What does <code>logical(0)</code> mean?</p>
  
  <p><strong>Question 2</strong>: I would have expected a TRUE/FALSE as the return value. This is  because he talks about the rules for coercion in R, specifically that Logical &lt; Integer &lt; Double &lt; Character (Least flexible to most flexible). Hence, I assume that <code>NULL</code> is of type Logical.</p>
  
  <p>I am not really sure where <code>NULL</code> fits into this equation. I'd appreciate any explanation.</p>
  
  <p>Thanks in advance.</p>