title: string.Join() doesn't work as expected
body: <p><img src="https://i.stack.imgur.com/LvwZq.png" alt="enter image description here">Feeling a bit stupid here. Maybe I'm missing something, but why doesn't the following simple call work as expected:</p>
  
  <pre><code>String.Join(" ", "CSharp".ToCharArray())
  </code></pre>
  
  <p>You'd expect it to return "C S h a r p", but interestingly it returns "CSharp". Moreover, the following call returns correct results:</p>
  
  <pre><code>String.Join(" ", "CSharp".ToCharArray().ToList())
  </code></pre>