title: PHP detect variable length string contains any character other than 1
body: <p>Using PHP I sometimes have strings that look like the following:</p>
  
  <ul>
  <li>111</li>
  <li>110</li>
  <li>011</li>
  <li>1111</li>
  <li>0110012</li>
  </ul>
  
  <p>What is the most efficient way (preferably without regex) to determine if a string contains <em>any</em> character <em>other</em> then the character <code>1</code>?</p>