title: Why can't variable names start with numbers?
body: <p>I was working with a new C++ developer a while back when he asked the question: "Why can't variable names start with numbers?"</p>
  
  <p>I couldn't come up with an answer except that some numbers can have text in them (123456L, 123456U) and that wouldn't be possible if the compilers were thinking everything with some amount of alpha characters was a variable name.</p>
  
  <p>Was that the right answer?  Are there any more reasons?</p>
  
  <pre><code>string 2BeOrNot2Be = "that is the question"; // Why won't this compile?
  </code></pre>