title: Regex to match if no space is found
body: <p>I have this: </p>
  
  <pre><code>^.*(?!.*[^\S])(?=.*[a-zA-Z]).*$
  </code></pre>
  
  <p>And this does not match if the string has a space at the end. </p>
  
  <p>I'm trying to make it so that it matches only if the string does not have a space anywhere, not just at the end. How can I do this?</p>