Do browsers behave differently towards JavaScript's codes?

Answer 1

Yes. And some browsers have Javascript turned off by default.

Answer 2

Yes. IE treats some Javascript commands differently then Forefox does. Then add Netscape, Opera, etc., and you have a nice collection of problems. All of the browsers also treat some HTML commands differently, they draw tables differently, etc. And different versions of the same prowser (such as IE 5 and IE 7) may run things differently. So when designing a web page, you need to be sure to test it in several browsers to be sure that it works on all of them. Plus, you will want to try them at different resolutions (800, 1024, 1280, 1600, etc) to see how the page "shifts" at those sizes.

Plus, some user may have javascript disabled on their browser, so it will not run at all on those PCs.

If you look around, there are free HTML codes available for detecting the different browsers. You can then have them redirected to a different version of a page if they are running Firefox instead of IE, etc. You can also detect for javascript being disabled and put up a warning box telling them to enable it if needed.

Answer 3

there are standards to be followed. Firefox follows the most. Then Safari+kthml, then opera, MS IE comes in at last place.

there are proprietary extensions that only work in 1 browser. MS IE is the biggest violator!

some standards are done wrong, again MS IE wins the prize for the most things done wrong and the most kludgey workarounds.

ECMAscript (the registered name for javascript) must behave in a certain predictable manner. simple JS will work on all. but when you manipulate pages via the dom.... they crack!

Answer 4

Yes. Not only do the browsers themselves vary, but so do the ways in which _people_ set them up. For instance, a lot of people entirely deactivate JavaScript.

So, in answer to the question between the lines - yes, you need to do compatibility tests on your site, and possibly write alternative versions for different users.

Rawlyn.