在使用JavaScript库/框架之前要学习什么？

Question

It seems that many of the JavaScript questions are answered by the simple use of pushing a library, without taking into account the person asking the question. I think libraries are great myself, but sometimes I think that we're too quick to throw a library down someone's throat.

Imagine a person asks a question and it's apparent that they barely know JavaScript. They're just using code they found and piecing it together with other code, and really have no firm foundation to work on. To add a library on top of that flimsy foundation seems like a disaster waiting to happen.

With that in mind, what JavaScript / programming / web browser concepts do you think are necessary to understand before a library/framework is introduced to a person? Should a framework / library be part of the learning process?

I don't think someone has to grasp absolutely everything to use a library, I just think some people would be better served with a "Library X might help solve your problems, but before you do that, you might want to read up on the following concepts", rather than just a "use library x" answer.

Answer 1

What you should learn are some fundamental programming techniques:

• closures
• continuations
• function objects / what a "first class" function is
• JavaScript object oriented design
• difference between "prototype" languages and traditional Object Oriented languages
• Absolutely firm grounding in HTML and CSS: standards, tricks, and various browser compatibility issues
• UI Design Principals

With that in mind, today its practically impossible to develop without a library. I recommend Dojo but others use jQuery, YUI, etc...

When choosing a library, you need to have a firm understanding of what problem you are trying to solve. Is it browser abstraction? dealing with communication? charting? animations? graphics? UI toolkits?

Each library has its "niche", so you need to really know what you're specific problem domain is and in turn choose a library accordingly.

Answer 2

我建议使用实体库，并找到一本有关JavaScript的好书 。

Answer 3

I think that one reflex reaction to a "how do implement X" is "don't reinvent then wheel", and this is generally good advice. I think that if you have to ask how to do something reasonably complex, and it's already in a library then you're going to waste massive time trying to piece together something from a few answers on SO.

So barring the obvious: learn the syntax of the language, learn how to debug etc., by and large a library is the right answer. And that's not just to say "Use the library, disengage brain" it also means "Study the library, look at the issues it's solving - you didn't realise your problem was so complex? Well the folks who put hours and days into the library studied the problem in some detail and probably developed the library by using it extendsively. Study the implementation and learen how."

I think that studying good code is a very good way to learn.

Answer 4

Libraries bring similarities to browsers where so much is different from browser to browser. This is why, I'd suspect, people suggest their usage in various answers. Nothing is stoping anyone from reading a good js book if they want to actually understand what is going on, but we surely cannot shove books and tutorials down anyone's throat. You need to want to learn before that would be worth anything.

Answer 5

他们应该阅读此http://www.amazon.com/exec/obidos/ASIN/0596517742/wrrrldwideweb并在http://www.crockford.com/上查看一些链接。