<html> <head> <meta charset="UTF-8"> <script src="jquery-3.3.1.js"></script> <script type="text/javascript"> x=0; y=0; $(document).ready(function(){ $("div.over").mouseover(function(){ $(".over span").text(x+=1); }); $("div.enter").mouseenter(function(){ $(".enter span").text(y+=1); }); }); </script> </head> <body> <p>不论鼠标指针穿过被选元素或其子元素，都会触发 mouseover 事件。</p> <p>只有在鼠标指针穿过被选元素时，才会触发 mouseenter 事件。</p> <div class="over" style="background-color:lightgray;padding:20px;40%;float:left"> <h2 style="background-color:white;">被触发的 Mouseover 事件：<span></span></h2> </div> <div class="enter" style="background-color:lightgray;padding:20px;40%;float:right"> <h2 style="background-color:white;">被触发的 Mouseenter 事件：<span></span></h2> </div> </body> </html>