x
 
<!DOCTYPE html>
<html>
<head>
<script src="/jquery/jquery-1.11.1.min.js">
</script>
<script>
$(document).ready(function(){
  $("button").on("click",function(){ 
    var version = $().jquery; 
    alert("You are running jQuery version: " + version); 
  });
}); 
</script>
</head>
<body>
<button>显示版本号</button>
</body>
</html>