【Javascript】【jQuery】jQuery实现回到顶部功能

    
        

        
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        * {
            margin: 0px;
            padding: 0px;
        }

        #content {
            width: 100%;
            height: 4000px;
            background: linear-gradient(yellowgreen, orange, yellowgreen);
        }

        #top-scroll {
            width: 80px;
            height: 80px;
            background: dodgerblue;
            position: fixed;
            right: 10px;
            bottom: 10px;
            display: grid;
            justify-items: center;
            align-items: center;
            -webkit-user-select: none;
            cursor: pointer;
            color: white;
        }

        #top-scroll:hover {
            border: white 1px solid;
        }

        #top-scroll:active {
            border: white 2px solid;
        }
    

    
    
        $(() => {
            $("#top-scroll").click(() => {
                let sy = $("html").scrollTop();
                let dy = sy / 200 * 10;
                //500ms内滑动到顶端，每个50ms滑动一次
                let intervalId = setInterval(() => {
                    sy = sy - dy;
                    if (sy