title: regular expression to match 4 or more identical characters
body: <p>I need regular expressions to match the below case.</p>
  
  <p>4 or more consecutive identical characters/numbers; e.g. 1111, aaaa, bbbb, 2222, etc.</p>
  
  <p>I tried this pattern matching</p>
  
  <pre><code>Pattern pattern = Pattern.compile("([a-z\\d])\\1\\1", Pattern.CASE_INSENSITIVE);
  </code></pre>
  
  <p>But i found that it matches only 3 or more identical characters.</p>
  
  <ol>
  <li><p>Please let me know what change i need to make it match 4 or more identical characters.</p></li>
  <li><p>Also i need to check for special character "\" . Please tell me how i need to add in the pattern matching statement ...do i need to give as "\\" ?</p></li>
  </ol>