What benefits are there to native JavaScript development?

Question

Given how much simpler jQuery development is, when compared to native JavaScript, what makes people forgo libraries like jQuery altogether?

Is this because jQuery has limitations or it is slow? I mean, if jQuery is so easy compared to native javascript, what reasons do people have to still use pure javascript?

Answer 1

Let's talk about cars.

Oh wait, we already did - remember that time we met, a few weeks ago, over steak and drinks? That was a great stake. We talked about cars. In fact, you seemed to be quite the expert on cars. You were able to explain, in detail, all of what's right and wrong and exciting about the latest Formula 1 race. You knew by heart all of Lamborghini's models, including their price and availability, you even had thoughts of purchasing your own Ferrari 599 GTB Fiorano, and currently saving up for it (bet the steak dinner didn't help much.)

While explaining the faults of Toyota in a great, excited voice, you suddenly jumped from your chair and screamed into the air, waving your fists about: "Damn it all, I'm a magnificent expert on all things related to cars! I'm gonna be a car mechanic!"

So you were. You had an interview, the Boss Man was just as impressed as I with your knowledge, and you were hired. The first client came in. His clutch was broken. You inspected it, and didn't know what to do. As a matter of fact, you had absolutely no idea how to follow the advice the Boss Man gave you. You're fired.

But how could this be!? You know everything about cars! Except for...everything about cars. You can very well know your dream car has a V12 engine, but you don't know what that actually means.

So you're not a car mechanic, really - you're a car enthusiast. And until you learn how cars work, you will remain one.

Now let me ask you. How does $.fn.text work? And what about $.fn? What is that, really? How does $(something) return a gigantic thingy containing things, and what is this thingy exactly? Can you replicate their functionality, at least a bit, in theory even? Can you cope without jQuery?

Saying that "native js is hard" is just...false. First and foremost, because javascript as a language has nothing to do with the DOM, which is mainly what jQuery abstracts. Second because once you learn a bit about the DOM, you can already coarse through the most common cross-browser bugs. But just a little secret - everything is hard at first. Long division was a bitch in 5th grade.

As a second analogy for this answer: jQuery is to javascript-DOM (not javascript the language, just the DOM) like Array.prototype.forEach is to for. It works, for 99% of the cases. And it works well. But for that 1% which isn't covered, you need to know how to use the for loop, if only to be practical. This entire answer is based on the "purer" side of the question, and not even the technical side (the library's size, for example, and several other things as explained in Michael Dorrant's answer), because I love javascript, and when people seem to just throw it aside casually saying "pah, those silly javascriptians" and waving fancy white gloves, it gets down to morality.

If you can accept the fact that you'll always be a javascript enthusiast, then who am I to stop you? But if you want to be a javascript programmer, you first have to have the knowledge to at least choose between using jQuery (or any other library) and not using a library. Learn the DOM. Learn how to use it. Write your own small library or just some collection of helper functions. And if then, when you are knowledgeable in the DOM, you choose to use jQuery - godspeed. Laziness is awarded for those who worked hard.

Answer 2

Reasons I know:

• when the need is extremely minimal, say 1 on-click.

• when download speed is critical and the jquery library is too large AND you don't have to write much (custom) code to replace it.

• when integrating with other technologies, sometimes raw js is better.

• when working on a legacy system (aka 'production) already written in js with established patterns.

Answer 3

jQuery is simply a framework – a set of tools written in Javascript. By using that set of tools you are still using Javascript. Some people prefer to write Javascript using the tools jQuery provides, some choose not to, other choose other sets of tools.

Some reasons you might want to write "pure" Javascript without jQuery:

• pages load faster without including extra jQuery files
• some frameworks may be incompatible with jQuery
• the code being written doesn't do anything that jQuery helps with
• the code is being written for others to use, and requiring jQuery as a dependency would make sharing more difficult
• the code author wants more control than jQuery provides

Answer 4

In the browser environment you need a cross browser normalization tool. Such a tool comes in two flavours

• wraps host objects with new objects which behave the same way across browsers
• extend host objects to implement the DOM API.

Generally you can use these utilities in one of three ways

• use small functions like addClass or setText throughout your code when and where you need them
• write your own cross browser normalization library
• use an existing one.

You need some mechanism of normalization otherwise you get zero cross browser support.

As for using an existing one, that's fine. I just wouldn't use jQuery. Personally I'm currently writing my own library (DOM-shim it fixes browsers without exposing a foreign propietory API. It turns your browsers into a single well behaved standardized browser).

Answer 5

jQuery, as any library or framework, adds another layer of bugs. I love it, but I've also lost a day looking for a bug that turned out to be in jQuery core and not my code (a rare occasion, but not that rare).

Other than that I don't find any other reason not to use it:

• The overhead is minimal, especially if you go with the hosted Google version,
• It helps less experienced Javascript developers write cleaner and more efficient code,
• It's mostly cross-platform, which can be life saving when you have to deal with older browsers,
• The huge gallery of plugins help me write prototypes in very short times,
• The DOM makes sense,
• blah blah blah...

BUT it should be never be used as a substitute of Javascript knowledge. If you don't know how to do it in pure Javascript, you may get away with a library initially but in the long run you are going to pay for it.

And of course there are all of us who've been locked in mortal combat with IE6 for quite a few years, and won't easily let go of our old school tricks in favour of a shiny new toy.

Answer 6

If you don't need DOM abstraction, cross-browser and legacy browser support - you can easily go without jQuery.

This is the case when you are developing browser extensions, greasemonkey scripts (sometimes), number-crunching stuff, developing for Node.js or other non-browser environments.

Answer 7

As you will be aware jQuery is a general purpose framework which provides a lot of methods which many of us don't use in our projects. (Some of them I haven't used at all)

There are two main reasons for not using JQuery or any other well established frameworks.

1. The project is not big or complex enough to use such a framework: In this case, the coder takes a informed decision based on his experience and knowledge in JavaScript. This will help him to reduce the page weight and also more control on the code.

2. The coder develops his own framework I have seen a project in my company which has it's own js framework. Reason what they quote is that if they are using jQuery and there is any bug to fix in it, they have to wait till the next version. Moreover, if there is a feature to be added, they need to ask the jQuery team for it or add a plugin even though making it a plugin won't be a good idea (example which they gave was that they have been using .live similar thing in their framework even before it was officially added to JQuery). Having your own framework gives you more control to the code. The disadvantage is that you need to reinvent the wheel regarding browser compatibility issues etc. Moreover, if the development process is not good, your framework will bloat and will only increase the time to maintain it.

Answer 8

Along with the other answers here, especially Michael Durrant's, I would saw speed is a major reason for me occasionally choosing to use raw JavaScript.

Lately I have been working on a lot of animations or other CPU-intensive tasks and some times raw JavaScript is much, much faster than if I go through jQuery.

One example is where I wanted to change the opacity of a position: fixed element in relation to how far down on a page a user has scrolled. The effect was way too slow when I used jQuery for this, causing scrolling to be jerky and the fade effect was ruined. I switched to using straight JavaScript and everything was silky smooth in all but IE <= 8.

Answer 9

I need to preface my answer with some open honesty. I love jQuery. It makes my life massively easier, and makes JavaScript code more declarative, which is the way I believe things should work.

jQuery does many things…

Yes you can add plugins
Yes you can extend selectors
Yes it simplifies animation

but jQuery doesn't do everything

Have you ever tried working in multiple window contexts with jQuery? jQuery sucks at dealing with different window contexts because it retains the original window and document context from the window in which it was called.

I've written some code here and there to make popouts*, and jQuery can simply get in the way of what I'm trying to accomplish. Adding a new reference to jQuery in the child window can often make things worse by making it more difficult to tell which jQuery context is being used.

_{* think of Gmail's popout for composing an email in a new window, not spammy advertising}

Use it when it makes code simpler

The time to use jQuery is when you can make your code simpler, shorter, more readable, and faster.

The time to not use jQuery is when it wont make your code simpler, shorter, more readable, or faster. If you need to fine-tune load timings, you may not want to use jQuery because of the event overhead.

Answer 10

I can add two more reasons that weren't mentioned:

1. When I pick up brand new technology, a lot of times, I would start with a lower level constructs before going to higher-level ones. I'm primary C++/C# developer, but a while ago when I first started playing around with HTML/CSS/Javascript, I chose not to use any framework because I wanted to first get understanding of the technology (i.e. Javascript language itself) that those frameworks are built on top of.

   • Having said that, I've since discovered jQuery and would never want to go back to coding by hand what jQuery can do for you in 1-2 lines of code.

2. I don't know how common this is, but to me it seems that there's a lot of people who when they see the next framework/technology/language, their first response is, "not another API for me to learn!" They don't care how easy jQuery is but simply see it as standing in the way between them and delivering work using their "true and tried" methods. This is the same category of people who refuse to use Boost Library or any of STL and continue to use malloc for just about everything. You asked why they pick pure Javascript over jQuery and in reality they never made the pick because most of the time they refused to evaluate jQuery in the first place and are perfectly happy with their current pace of development, no matter how slow it is.

Answer 11

jQuery is a library written in and for JavaScript. The idea is it makes all the difficult / tedious JavaScript things simple, thus speeding up development time and making your scripts much more likely to work cross-browser.

What makes jQuery to use :

• fast
• lightweight JavaScript library
• CSS3 compliant
• supports many browsers.
• The jQuery framework is extensible and handles DOM manipulations, CSS, AJAX, Events and Animations.

JavaScript is a language whereas jQuery is a library written using JavaScript.

Here are reasons that makes javascript to use rather than jquery:

1. It every time load the whole jquery script library with the page. It is drawback for peed/ fast query processing website.
2. Sometime jquery framework collapse/conflict with other.
3. If you are writing simple code for just for select a element and show alter then native javascript is much better.
4. If operations are small and performed within few line of code of javascript then it is not good to use jQuery

Due to there reason i like to use JavaScript to avoid jquery framework. It is much better to learn javascript rather depending on such library..

Even If you want to extend them you need to write code in JavaScript. which is also a big talk. Developers get dependent on these libraries, so to make control on projects JavaScript is better then using frameworks.

Answer 12

I think people use jQuery because it's simpler, easier, and more powerful, and because it helps them forget about IE. Besides, for customized functionalities people do use javascript. Try referring the DOC for more details