title: How to extract numbers from a string in Lua?
body: <p>I can't find how to do a simple regex in Lua. In every normal language it is:</p>
  
  <pre><code>string:match( "($1,000)", "[\d]+")
  </code></pre>
  
  <p>It returns: 1000 (if you concatenate matches).</p>
  
  <p>I thought <code>string.match( "($1,000)", "%d+") )</code> will do the job but it returns nil or 1.</p>
  
  <p>I don't understand it.</p>