Tryit Editor v1.8

Source Code:
<!DOCTYPE html> <html> <head> <script src="../../ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"> </script> <script> $(document).ready(function(){ $("button").click(function(){ $("li").removeClass(function(n) { if (n==0||n==1) {return "listitem"} else {return ""} }); }); }); </script> <style type="text/css"> .listitem { color:red; } </style> </head> <body> <h1>This is a heading</h1> <ul> <li class="listitem">Peter</li> <li class="listitem">Lois</li> <li class="listitem">Chris</li> <li class="listitem">Stewie</li> </ul> <button>Remove class "listitem" from the li elements with index 0 and 1</button> </body> </html>
Result:
W3Schools.com - Try it yourself