How to determine if we need to learn another javascript library?

Question

I studied jQuery and am still learning it. And then I heard about extjs. Extjs has its own ways of doing similar things in jQuery, and I don’t feel like I can remember both at the same time. My question is whether I should study as many libraries as they will develop, or I should just focus on one and deprive the additional functions that the new one introduces.

Answer 1

I use both ExtJS for full-fledged web applications (RIA) and jQuery to improve websites.

I tried using ExtCore (the LGPL ExtJS part limited to dom queries, animations, ... This is not as useful as jQuery.

But I would not create RIA with jQuery.

ExtJS4 ( ).

, , , , , , : , javascript .

Answer 2

PETS:

P = (E - T) * $*.80

• P = .
• E = HOURS (IE, , )
• T = , ( )
• $= (: $60, -)
• .80 - , , , .

(300 - 200) * $60, - *.80 → $4800

4800 , 5 .

;)

Answer 3

You have to decide which one you will use - you are likely to use only one at any time. Libraries often have compatibility modes, but I don’t think there is a reason to use two on the same page.