20171020.02 – 源码巴士

<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        div{
            width: 300px;
            height: 300px;
            border:1px solid red;
            background-color: pink;

        }

        .width{
            width:100px;
        }
        .yellow{
            background-color: yellow;
        }

    </style>
</head>
<body>
    <input type="button" value="测试改变样式" id="add">
    <div id="box" class ="yellow">miaovketang</div>

<script>
    var changeStyle = document.getElementById("add");
    var box = document.getElementById("box");

    changeStyle.onclick = function(){
        // box.style.width = "200px";
        // box.style.height = "200px";
        // box.style.fontSize = "28px";
        // box.style.backgroundColor = "blue";
        // box.className = "yellow width height"

        // box.classList.add("width");
        // box.classList.remove("yellow");
        box.classList.toggle("width");
    }


</script>   
</body>
</html>