close tab instead of whole browser in javascript code example

Example 1: javascript close current tab

window.close();//closes the current browser tab

Example 2: close browser tab javascript

//You are able to close a browser tab with an index.html page
//The code below from lines 3-13 are from the index.html page, it redirects you to another page
<!DOCTYPE html>
<html>
<head>

    <script type="text/javascript">
window.open("/folderDirectory/example.php"); 


     </script>
</head>
</html>
//The code below is from the example.php
  $(document).ready(function(){
    $("button").click(function(){
      window.close();
      });
  });//jquery is used to make the user click the button to exit 

//The code below should be placed in the html body, it is a button that closes the window when the user clicks on it
<button style="border: none;" >Exit</button>