老师，这里如果加节流锁怎么加？

来源：3-13 编程练习

慕UI4313976

2021-08-18 11:00:14

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>Document</title>
    <style>
        div {
            width: 300px;
            margin: 20px 0;
            line-height: 30px;
            background: yellowgreen;
        }
    </style>
</head>
<body>
    <button id="start">开始</button>
    <button id="stop">停止</button>
    <div id="box"></div>
    <script>
        const startBtn = document.getElementById('start')
        const stopBtn = document.getElementById('stop')
        const box = document.getElementById('box')
        var show = {
            content: "Hello World",
            timer: null,
            start: function () {
                // 在此补充代码
                startBtn.addEventListener('click',()=>{
                    clearInterval(this.timer);
                    this.timer = setInterval(()=>{
                        box.innerHTML += this.content + ' ';
                    },1000);

                },false)
            },
            stop: function () {
                // 在此补充代码
                stopBtn.addEventListener('click',()=>{
                    clearInterval(this.timer);
                },false)
            },
        }
         // 在此补充代码
         show.start();
         show.stop();
    </script>
</body>
</html>