Some problems about the whole lesson


Hi, everyone. I met some problems through out the whole lesson.

  1. From 1 to 10, The message "Uncaught ReferenceError: $ is not defined" keeps appearing below the console, before and after I click the "Save and Summit Code". Then from 11 on, the message becomes "Uncaught SyntaxError: missing ) after argument list". Yet, when I click the "Save and Summit Code" button, the code gets through.

  2. Though I have not actually seen, I guess when I move the mouse into and leave the 'div' part, some changes should happen, after the due code is summited. But nothing changes! Yet I can move forward, too!

I suspect these 2 result from 1 problem.

On the below page, some one said the 1st problem is about the DNS setting. Then I tried his solution but that does not help.

I try different browsers and Javascript function has been set to "allow". I have finished the previous Javascript part, and did not have such problems.

Could anybody help? Thank u in advance.

Replace this line with your code.


In China because of the GFW,many websites won't work correctly. So jquery failed to react in codes below
《script src="//"script》 --->these codes just can't work.

You can use "" instead or use VPN to 科学上网


Well, you do know the damned GFW. The weird thing is, now I can see those actions without trying your suggestion and the message "Uncaught ReferenceError: $ is not defined" no longer appears either!
BTW, how can I use "" instead of " initially.