title: regex: find one-digit number
body: <p>I need to find the text of all the one-digit number.</p>
  
  <p>My code:</p>
  
  <pre><code>$string = 'text 4 78 text 558 my.name@gmail.com 5 text 78998 text';
  $pattern = '/ [\d]{1} /';
  </code></pre>
  
  <p>(result: 4 and 5)</p>
  
  <p>Everything works perfectly, just wanted to ask it is correct to use spaces?
  Maybe there is some other way to distinguish one-digit number.</p>
  
  <p>Thanks</p>