Js research on obtaining the visible window size of various browsers

In my local test: it can be used in IE, FireFox, and Opera.

Document. body. clientWidth

Document. body. clientHeight can be obtained, which is very simple and convenient.

In the company project, Opera still uses

Document. body. clientWidth

Document. body. clientHeight

However, IE and FireFox use

Document.doc umentElement. clientWidth

Document.doc umentElement. clientHeight

It turned out to be W3C standards in the end of the http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">

If this line is added to the page

In IE: document. body. clientWidth => BODY object width

Document. body. clientHeight ==> BODY object height

Document.doc umentElement. clientWidth ==> visible area width

Document.doc umentElement. clientHeight => visible area height

In FireFox: document. body. clientWidth => BODY object width

Document. body. clientHeight ==> BODY object height

Document.doc umentElement. clientWidth ==> visible area width

Document.doc umentElement. clientHeight ==> visible area height?

In Opera: document. body. clientWidth => visible area width

Document. body. clientHeight ==> visible area height

Document.doc umentElement. clientWidth ==> Page Object width (that is, adding the bodyobject width to the marginwidth) document.doc umentElement. clientHeight ==> Page Object height (that is, the BODY object height plus the Margin height)

If W3C standards are not defined,

IE is: document.doc umentElement. clientWidth => 0

Document.doc umentElement. clientHeight => 0

FireFox: document.doc umentElement. clientWidth => Page Object width (that is, the width of the BODY object plus the Margin width)

Document.doc umentElement. clientHeight ==> Page Object height (that is, the height of the BODY object plus the Margin height)

Opera: document.doc umentElement. clientWidth => Page Object width (that is, the width of the BODY object plus the Margin width)

Document.doc umentElement. clientHeight ==> Page Object height (that is, the height of the BODY object plus the Margin height)

From the developer's point of view, it is much easier to use fewer objects and methods than to use the latest standards.