第四段代码的答案为什么是354*53

<script type="text/javascript">

var w=document.documentElement.clientWidth||document.body.clientWidth;

var h=document.documentElement.clientHeight||document.body.clientHeight;

document.write(w+"*"+h+"<br>")

var w=document.documentElement.clientWidth;

var h=document.documentElement.clientHeight;

document.write(w+"*"+h+"<br>")

var w=window.innerWidth;

var h=window.innerHeight;

document.write(w+"*"+h+"<br>")

var w=document.body.clientWidth;

var h=document.body.clientHeight;

document.write(w+"*"+h)

</script>