在线运行代码 - 菜鸟教程

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(cainiaoplay.com)</title>
<script>
function clickCounter() {
    if(typeof(Storage) !== "undefined") {
        if (sessionStorage.clickcount) {
            sessionStorage.clickcount = Number(sessionStorage.clickcount)+1;
        } else {
            sessionStorage.clickcount = 1;
        }
        document.getElementById("result").innerHTML = "你在按钮上已经点击了 " + sessionStorage.clickcount + " 次。";
    } else {
        document.getElementById("result").innerHTML = "Sorry, your browser does not support web storage...";
    }
}
</script>
</head>
<body>
<p><button onclick="clickCounter()" type="button">点我!</button></p>
<div id="result"></div>
<p>点击按钮查看数字变化。</p>
<p>关闭浏览器并重新打开，看看数值是否重置了。</p>
</body>
</html>
源代码

动行结果
