Width and height different in CSS and HTML

Question

Say I have a div . If I give it a height and width of 500*500px in HTML code, like this: <div width="500px" height="500px">test</div> it will not have dimensions of 500*500px unless it's filled with enough code/text to push it to those dimensions. However, if I set the exact same width and height with CSS (either inline CSS or external document) like this: <div style="width:500px; height:500px;">test</div> the dimensions are always what I set.

Why is there a difference?

Answer 1

div标签没有属性width和height 。

Answer 2

Doing this isn't valid syntax. You cant add width & height attributes to a DIV the same as you can to a table or an image tag.

<div width="500px" height="500px">test</div>

This is valid syntax:

<div style="width:500px; height:500px;">test</div>