菜鸟教程在线编辑器

AI 编程工具
 
                <!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>

<p>判断屏幕（screen/viewport）窗口大小。</p>

<button onclick="myFunction()">点我</button>

<p id="demo"></p>

<script>
function myFunction() {
    var x = document.getElementById("demo");
    if (window.matchMedia("(max-width: 700px)").matches) {
        x.innerHTML = "窗口小于或等于 700 像素";
    } else {
        x.innerHTML = "窗口大于 700 像素";
    }
}
</script>

</body>
</html>
              