event事件延伸以及阻止方式

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        #div1{
            height:200px;
            width: 200px;
            background: gold;
        }
        #div2{
            height: 100px;
            width: 100px;
            background: royalblue;
        }
    </style>
</head>
<body>

    <div id="div1" onclick="f1()">
        <div id="div2" onclick="f2(event)"></div>
    </div>
</body>
<script>
    function f1() {
        alert("div1");
    }
    function f2(e) {
        alert("div2");
        e.stopImmediatePropagation();  //阻止点击div2模块是会向div1触发
    }
</script>
</html>