title: Regex to match a number with something or nothing
body: <p>I must match a string that can come up in 3 ways(numbers are variable and only for example illustration).</p>
  
  <pre><code>1-100 of 
  1-25 of 
  &lt;nothing&gt;
  </code></pre>
  
  <p>So I need a Regex that matches strings like "1-100 of ", "1-25 of " or nothing.</p>
  
  <p>How could I accomplish this with a regex?
  Thank you very much!</p>