title: Angular ng-pattern regex not working
body: <p>I'm trying to create a validation for an angular input field which accepts only the a-zA-Z0-9 characters and special characters ".”(full stop), "_" (underscore), "@"(at sign) </p>
  
  <p>I can't seem to get the hang of it.</p>
  
  <p>I tried: </p>
  
  <pre><code>ng-pattern="/[a-zA-Z0-9_@.]+/"
  </code></pre>
  
  <p>requirement:</p>
  
  <ul>
  <li>It can contain only alphabetic characters</li>
  <li>it can contain alphabetic and numeric </li>
  <li>It can contain alphabetic numeric and mentioned special characters</li>
  <li>It cannot contain space</li>
  </ul>