title: How to remove all non-alphanumeric and non-space characters from a string in PHP?
body: <p>I want to remove all non-alphanumeric and space characters from a string. So I do want spaces to remain. What do I put for a space in the below function within the [ ] brackets:</p>
  
  <pre><code>ereg_replace("[^A-Za-z0-9]", "", $title);
  </code></pre>
  
  <p>In other words, what symbol represents space, I know \n represents a new line, is there any such symbol for a single space.</p>