What issues cannot be solved by jQuery as compared to JavaScript ?

Question

Possible Duplicate:
Is jQuery always the answer?

Now-a-days everyone is talking only about jQuery at my work place, there are some Sr. Developer who work mostly with JavaScript and they have their rights reserved for jQuery. I am kind of little confused between jQuery vs JavaScript

What are the programming challenges which cannot be solved by jQuery and one has to go to JavaScript only or what are pros and cons of using jQuery vs JavaScript ?

Update - Would it be fair to say that there is no programming issues which can be solved by JavaScript and not solved by using jQuery Framework ?

Update 2 - So far from answer I guess it is ok to say that what we can do in JavaScript can be done using JQuery, correct me on this if am wrong listing the programming challenges which can't be dealt with using jQuery as compared to JavaScript ?

Answer 1

jQuery is a library written in JavaScript. By definition, there is nothing you can do in jQuery that cannot be done with JavaScript (you could write your own functions to do anything that jQuery does).

Of course, there are lots of things you can do more easily by using a library/framework, which is why they exist.

Pros of using a library like jQuery, mooTools, Dojo, YUI, etc:

1. Saves you time in writing and debugging convenience functions
2. Cuts out need to write boiler plate code
3. Smooths over cross-browser differences

Cons:

1. Your users may download a lot of code they don't need for your particular application
2. You won't have complete control over or understanding of every line of code on your site, unless you want to become an expert in that particular library
3. Their bugs become your bugs

Answer 2

jQuery is a javascript framework (written in javascript). It adds advanced selectors (for easily traversing the DOM), event handlers, easy animations, and simplified AJAX request. All 'programming issues' that are solvable in JavaScript are also solvable in jQuery (as jQuery simply adds functionality to JavaScript).

Answer 3

I use jQuery for rich ajax and ui interaction. I use plain javascript for everything else.

Mind you, since switching to MVC I use jQuery for the ajax and ui interaction and c# for everything else because i like to control things there rather than rely on the client box.

Oh and with jquery I no longer worry about which browser is being used. It just works which is such a nice change.

Answer 4

jQuery is a JavaScript library, so by definition anything that can be done in jQuery can be done in JavaScript, and you have to use JavaScript to use jQuery.

Answer 5

one should know that jQuery is just JavaScript...

jQuery just let you get off the cross browsers issues and let you do less coding..

Answer 6

jQuery is written in JavaScript, therefore everything you can do in jquery you can do it also in Javascript.

But jQuery saves you a lot of time, and introduces you to the "Selectors" that help A LOT.

Answer 7

Jquery and Javascript are not two different things.

If you are using Jquery, you're using Javascript.

A question that would make more sense, is whether to use Jquery in your Javascript, or just Javascript on its own.

One of the great things about Jquery is that it doesn't force you into doing everything with Jquery; you can use it as just one more tool in your larger Javascript based application. It even plays well with other Javascript libraries.

Answer 8

One pro of using jQuery - or other frameworks - is that it smoothes out the rough edges of JavaScript. Instead of getting caught up in writing code to deal with a browser-specific issue, you can stay focused on your task at hand and take advantage of the efforts of the jQuery core team and the community to maintain the framework to handle those issues.

Answer 9

Not really a programming challenge but one point that has to be carefully considered (and evaluated in the specific context):

High performance

With jQuery it is tempting to use the "easy" solution. For example, you could select all elements of a certain class that are visible with

$('.class:visible');

On large pages, this can take up to a second. Everything that is slower than 100ms is noticeable by the user and decreases usability.

---

In general it is to say: Use the selector API wisely. Don't make unnecessary calls. Most of the time it might work quite well but there are cases where it really takes time.

Answer 10

There are many things which you can't do in jQuery which Javascript can do.

The problem is, you're comparing apples to oranges.

jQuery is a library, it is not a language.
When using jQuery, you write Javascript code. jQuery doesn't need to do the same thing as Javascript, because it sits on top of Javascript, using Javascript.

For example, there's no jQuery function that lets you concatenate strings.
But there doesn't need to be, since Javascript can already concatenate strings. There's no need for jQuery to re-implement that functionality.

Does that mean that jQuery can do less than Javascript? Mu.

You can certainly do more in Javascript than you can do in jQuery. You can do anything in Javascript, while jQuery only provides a handful of shortcuts for often used functionality. What would take many lines of code to do correctly in plain Javascript is summarized in one function call in jQuery. The secret is that jQuery contains all these plain lines of Javascript, which someone has already written for you, so you won't need to. It's just a collection of Javascript snippets, nicely packaged up in objects and functions to make your life easier; it's not a completely different thing.

Any functionality that jQuery or one of the jQuery plugins does not provide a shortcut for, you will have to write in plain Javascript. While you're at it you may want to write it as a jQuery plugin to make it reusable.

Answer 11

I do not like the blanket statement of "jQuery eliminates many cross-browser issues". It is somewhat misleading as what jQuery primarily does is eliminate many cross-browser issues related to the DOM. To me the bigger problem in web development is cross browser issues related to CSS rendering, as these cannot be simply coded around. With CSS we are pretty much stuck with what we got (and unfortunately that is far far less than even plain Javascript).

Sure there are Javascript libraries that actively modify styles per browser in an attempt to achieve more consistency, but I consider such methods an ugly hack. Stuffing cross-browser logic in Javascript functions is child's play compared to achieving even similar page layout results between IE and...everything else using pure CSS.

Honestly whenever I'm writing code for a single browser or...not IE, I tend not to use jQuery. Defining a few simple wrapper functions around document.getElementById/getElementsByTagName/evaluate can often achieve almost the conciseness of jQuery without the overhead. Really, without the tangle of cross browser BS to deal with, whipping up helper functions on an as-needed basis is a painless and almost enjoyable task, especially if you cast off any inhibitions about extending built in Javasciprt/DOM objects.

But if you are really looking for situations where jQuery is utterly useless, try writing server-side Javascript. No DOM, no CSS, no IE, just pure Javascript bliss. Ah Node.js, where hath you been all my life.

Answer 12

This may be nit-picking, but you can't select the input below by its value attribute in jQuery (stolen from this question). The problem is with the regex parser that jQuery uses. Read up bobince's excellent answer on the issue.

<input id="a" type="text" value="a'b]<p>" />

The CSS selector for the value attribute with escaping would be [value=a\'b\]\<p\>].

In JavaScript, we would need an extra slash for the string. The escaped selector works with Selectors API, but not with jQuery:

document.querySelector("[value=a\\'b\\]\\<p\\>]"); // works

$("[value=a\\'b\\]\\<p\\>]"); // doesn't work

There you go, the holy-grail example you were looking for.

Nit-picking aside, jQuery moves rather fast and the above issue is solvable by writing a more robust parser (an actual parser, not regex). jQuery 2 has plans for some amazing features which I am looking forward to such as reverse selectors (rumored).

div < span.name

This would select all div's which contains a span having the class name. Till now, all selectors were uni-directional (top to bottom), and we had to traverse up the DOM hierarchy to get a higher element, but constructs such as the above will make for a much more powerful selector engine.

Answer 13

I still don't think that the maintainability issues, that were the nightmare of many developers existence when using JavaScript, have been solved entirely by JQuery. You still land up with a lot of java script code, over time it can become spaghetti, it could be that the devs at you work would rather stick with the devil they know.

On an enterprise project, where the cost of failure is so high i.e. people can die etc.. they may feel more comfortable with something they know and have an established track record with.

Answer 14

jQuery is a Library of commonly used functions that make working with DOM elements easier. There's many inconsistencies between browsers related to working with HTML elements (selecting, styling, manipulating, etc) that require lots of if/else browser sniffing techniques.

What jQuery neglects is what JavaScript - the language - does really well. And what JavaScript got right was Object inheritance.

jQuery is not object oriented. Nor does it try to make extending or editing existing objects currently at your disposal. In that sense, jQuery cannot be considered a "Framework".

So if you're looking to do work that involved Objects and Extendability - You're going to have to use Plain-ol javascript. If you are going to manipulate elements in the document - You're going to want to use jQuery or some other library/framework.

Some Frameworks provide BOTH. They make dom manipulations easier, as well as provide a classical inheritance model. See Dojo/Mootools.