<!DOCTYPE html>
<html>
<body>
<p id="demo"></p>
<script>
var w = window.innerWidth
|| document.documentElement.clientWidth
|| document.body.clientWidth;
var h = window.innerHeight
|| document.documentElement.clientHeight
|| document.body.clientHeight;
var x = document.getElementById("demo");
x.innerHTML = "浏览器内窗宽度：" + w + "，高度：" + h + "。";
</script>
</body>
</html>