title: regex to mask IBAN
body: <p>I want to mask IBAN. I have to show only first 7 characters and last 4 characters.</p>
  
  <p>Example: </p>
  
  <p>Input: </p>
  
  <pre><code>PL61109010140000071219812874
  </code></pre>
  
  <p>Output: </p>
  
  <pre><code>PL61109***********2874
  </code></pre>
  
  <p>I wrote the following regex:</p>
  
  <pre><code>(?&lt;=.{7})(.*)(?=.{4})
  </code></pre>
  
  <p>but js do not support lookbehind</p>