why body is defined in window object

Question

I was just playing around in the console, and noticed that if I type:

body it returns <body>...</body>

This is obviously the same as window.body, which therefore also returned <body>...</body>

Then document.body also returns <body>...</body> as expected, as the body is part of the document object, and as far as I was aware, not the window object.

For this reason I expected window.body to return undefined.

Then I checked window.head which returned undefined.

This is the result I expected to happen with window.body

Finally, document.head returned <head>...</head> as expected.

Can anyone explain where window.body comes from? A search on google, and stackoverflow couldn't answer this one for me.

I'm getting `undefined` for `window.body` in Chrome. Please specify which browser you're using. — JJJ, Mar 15 '16 at 09:12
I'm also getting `undefined` on Firefox. Could be an artifact of your browser or of the page you have loaded. — Frédéric Hamidi, Mar 15 '16 at 09:13
Did you do a `body = document.body` earlier in the console? That's where `window.body` comes to life. — Sergio Tulentsev, Mar 15 '16 at 09:13
wow! very strange. check if you run it on this page? https://www.youtube.com/watch?v=-q1z8BPFItw When I opened a new tab it showed `undefined` — Paul Fitzgerald, Mar 15 '16 at 09:14
[Do DOM tree elements with ids become global variables?](http://stackoverflow.com/questions/3434278/do-dom-tree-elements-with-ids-become-global-variables) — JJJ, Mar 15 '16 at 09:15

score 0 · Answer 1 · edited Jun 20 '20 at 09:12

The window.body element is not the same as the document.body element unless some javascript on the page has already assigned that as a helper method.

As mentioned in the comments on your question, the default would be undefined for window.body (and hence simply body).

Here are 3 screenshots from Chrome, Safari and Firefox consoles showing what the google homepage (google.co.uk in this case) sets as the result of window.body compared with document.body. Clearly not the same as document.body, therefore you can tell they've done that themselves for a particular reason (as had the page you're looking at possibly):

Chrome

Safari

Firefox

Hope that helps.

why body is defined in window object

1 Answers1

Chrome

Safari

Firefox