Yes, a sufficiently smart developer can write good code in Javascript. But there are very few people who I'd trust to write financial code in Javascript, and I think all of them would use a better language rather than expending the effort working around its deficiencies.
Almost nobody modifies Object.prototype, and we now have plenty of APIs to deal with that - defineProperty, seal, freeze, etc.
0.3 * 3 => 0.8999999999999999
And the example you have given is a problem with all floating point implementations, not just Javascript. You will get that exact same answer in C, Java, etc.
The only way to avoid this is to represent rational numbers directly, without simplification. For example:
(3/10) * 3 => (9/10)In the example given, using node-bignum and assuming our precision is a thousand of a cent:
big(30000).mul(3) => 90000
Here's a relevant example,
2^26 * 2^26 == 2^52
that said, you could still write your own bigint class if you need precision beyond that.
The others I don't really mind: I like writing event-loop code over threads, and have never once run into Object.prototype problems in the wild.
First, running the same UI code on the front-end and back-end will enable the best performing apps across platforms. Imagine being able to run a rich client on a powerful PC that just talks to an API and does all the rendering as a single page app, while simultaneously being able to serve up pure HTML/CSS to mobile devices and search engines. Being able to run code on the server or client as needed solves too many problems to ignore.
But on the other hand, javascript flexibility and lack of type system will inevitably cause problems as the codebase grows unless you have a good lead developer to define standards and an iron-fisted approach to code reviews.
Personally I think coding standards are a stretch with a language as wild as javascript, and a higher level language to enforce certain things is the best way to reconcile these two problems. I can even imagine supplementing with something like (for instance) a Haskell library that lets you generate JS code for interfacing with the back-end in a provably correct fashion, and plugging that into the UI code.
-TypeScript definitions for many libraries, such as express are out of date and require modding to use.
-Visual Studio has no built in support for TypeScript with Node for debugging, but it has been mentioned as likely to be added by the TypeScript team eventually.
-There are third party plugins for Node in Visual Studio for debugging, but none support TypeScript yet.
I've found the best solution thus far is Intellij IDEA or WebStorm, as it has support for both Node and TypeScript.
i use typescript professionally, i use vs2013 for writing code, webstorm for debugging / testing
The problem that TypeScript solves is that the web platform is in direct conflict with Microsoft's monopolies in PC gaming and business productivity software (Office). Confusing developers into thinking that JavaScript needs types leads them down the path of statically typed languages, i.e. C# and Microsoft's proprietary and closed .NET Framework and software ecosystem.
https://www.dartlang.org/articles/style-guide/#type-annotati...
Because instead of developing languages to run on top of them, people just designed languages to run on the same platform. The browser environment is a special case where the only common feature of the platform that is available to target is JS, there's no common VM underlying it, so replacements target JS.
Though its worth noting that while it may be true that no one developed a language to run on top of C++, C++ was originally implemented as a language that was preprocessed into C and then fed to a C compiler, much the way that many JS alternatives are compiled to JS and then fed to a JS interpreter.
Clojure? Scala?
- structural typing for interfaces (which means that classes implicitly implement an interface if the definitions match)
- gradual typing (mainly the ability to convert between 'any' and other types implicitly, which makes it much easier to interact with JS libraries/port JS code to Typescript.)
More generally speaking, Typescript aims to solve the problem of maintaining large codebases by giving you the additional security of static typing. The idea is that many simple errors can often be caught by a compiler, but would be much more time-consuming to find otherwise.
if (obj && obj.quack && typeof obj.quack == 'function') obj.quack(); //looks like a duck
- Refactoring e.g. easily globally change a class member's name
- Type safety e.g. it will bark if you pass a string where an int is expected
- General IDE handyness e.g. 'Go to definition'
A really good demo here: http://channel9.msdn.com/Events/Build/2013/3-314
I coded exclusively in javascript from 2006-2011. Most of that time was spent at Meebo, where we authored one of the most sophisticated JS application in existence at the time. It was great stuff!
I've worked extensively with node.js 2011-mid2013, launching multiple backends written partially and exclusively in node. Lots of fun!
On https://github.com/marcuswestin I maintain multiple widely used open source projects, much of it JS.
In the past 4 weeks I've rewritten my current product's entire nodejs backend to a statically typed language. Why? Because static type analysis allows you to develop more accurate code faster and with lower maintenance cost.
I've been a strong advocate for "javascript everywhere" for a long time. However, these days I believe that there is exactly one fantastic use case for javascript: delivering rich application experiences in web browsers.
So you may be right: perhaps this line of arguing is fading. But in that case I'm a real outlier.
(and with all that said, the most important thing to consider is this: what tool will best allow you and your team to build and maintain your intended product?)
I've not used anything that allows for as easy modularity as node+npm lend themselves to... just because it's JS doesn't mean it's spaghetti that has blurry code sharing between the client and server.. it's not all meteor, even if that does have a lot to offer.
This statement may be true for you, but it's not for everyone.
It's a dangerous argument because it assumes that static types are going to somehow magically turn bad code into good code, or (by extension) bad coders into good ones.
Static typing is a not a solution to the problem of any deficiencies in the language, but rather the problem of people shooting themselves in the foot with it. It's admittedly a related problem, but a separate one.
> (and with all that said, the most important thing to consider is this: what tool will best allow you and your team to build and maintain your intended product?)
I'd defend the statement you quoted like this: all languages are type. Dynamic languages simply have exactly one expression type, "any". Specifying multiple types affords you strictly beneficial abilities. Static type checks is probably the most significant. Performance improvements and highly specific and accurate code editing assistance (e.g auto suggest) can also be significant.
But yes, you're absolutely right. Nothing but sincere effort, lots of practice, and critical thinking can make you a better programmer.
At the same time, a great carpenter becomes even so much better with a properly weighted hammer and an accurate lever.
:)
In other words, it's Turing complete. That's great but not exactly an argument for using JS server-side so much as a reason why it is possible. I love JS, but I also know what it was designed for.
> I believed, and still do believe, that statically typed languages are exactly what you want in the guts of your business logic.
He wasn't making a case against javascript for his shopping cart but rather against dynamic languages.
Now, you could certainly disagree with that as well, but it opens the discussion to a more correct one vs why you believe javascript is a mature language. Something the author actually agrees with.
Coming back and maintaining them a year later is a different story.
After developing almost exclusively in JavaScript for the better part of the past year (and doing a lot more in the previous 6), I'm convinced that this mentality is going to start fading as more and more developers become more capable and productive with JavaScript.
There's nothing inherently wrong with the language that prevents you from writing sufficiently complex and reliable systems to power something like a shopping cart, or anything else for that matter. The main thing that is missing at this point is experience and maturity in the JavaScript community at large, which is quickly changing as more and more developers start embracing the language.