title: Regex match exact number not if it exist in string
body: <p>My regex: </p>
  
  <pre><code>/3\b/
  </code></pre>
  
  <p>Matches:</p>
  
  <pre><code>103
  
  134,256,3
  </code></pre>
  
  <p>I want it to only match the lone 3. The number 3 will be a dynamic number så the regex has to match that exact number and nothing else. It cant match if the number exists in another number like in 103, then it should not match. 256 should match only 256 in the above and so on. I am stuck. Thank you.</p>