title: Regular Expression to validate Alphanumeric value in JavaScript
body: <p>I want to check if a string is STRICTLY ALPHANUMERIC in javascript. A valid string should not contain any special characters and must have atleast one uppercase or lowercase alphabet and a digit. </p>
  
  <ul>
  <li><code>aaa</code>, <code>1111</code>, <code>112@#</code>, <code>12qw#</code> : Invalid</li>
  <li><code>aaa111</code>, <code>12abc</code>, <code>abc123abc</code>, <code>12bc12</code> : valid</li>
  </ul>
  
  <p>Can anyone help me to frame my regular expression?</p>