title: What regex can I use to match only letters, numbers, and one space between each word?
body: <p>How can I create a regex expression that will match only letters and numbers, and <strong>one</strong> space between each word?</p>
  
  <p><strong>Good Examples:</strong></p>
  
  <pre>
  Amazing
  
  Hello World
  
  I am 500 years old
  </pre>
  
  <p><strong>Bad Examples:</strong> </p>
  
  <pre>
  Hello  world
  
  I am 500 years      old.
  
  I    am   Chuck Norris
  </pre>