JavaScript, like any programming language, has its own set of limitations. Here are a few examples of the limitations of JavaScript:
1. Single threading: JavaScript is a single-threaded language, which means that it can only execute one task at a time. This can lead to performance issues when working with large amounts of data or when running complex calculations.
console.log("Start");
setTimeout(() => {
console.log("Timeout 1");
}, 5000);
setTimeout(() => {
console.log("Timeout 2");
}, 0);
console.log("End");
In this example, the "End" message is logged before the "Timeout 1" and "Timeout 2" messages, even though the second timeout has a delay of 0ms. This is because JavaScript is single-threaded and can only execute one task at a time.
2. Limited precision of numbers: JavaScript uses a double-precision floating-point format for numbers, which can lead to rounding errors and inaccuracies when working with very large or very small numbers.
let x = 0.1 + 0.2;
console.log(x); // 0.30000000000000004
In this example, the result of adding 0.1 and 0.2 is not exactly 0.3 due to the limited precision of JavaScript's floating-point numbers.
3.Limited support for multithreading: JavaScript lacks built-in support for multithreading, which can make it difficult to take full advantage of multi-core processors.
let x = 0;
let y = 0;
for(let i = 0; i < 100000000; i++) {
x += i;
}
for(let i = 0; i < 100000000; i++) {
y += i;
}
console.log(x + y);
In this example, the two for loops are executed sequentially, one after the other, even though they could be executed in parallel on a multi-core processor to improve performance.
4.Limited support for concurrency: JavaScript has a callback-based model for handling concurrency, which can lead to callback hell and complex nested code, making it difficult to read, understand and maintain.
function asyncFunc1(cb) {
setTimeout(() => {
cb(1);
}, 1000);
}
function asyncFunc2(cb) {
setTimeout(() => {
cb(2);
}, 2000);
}
function asyncFunc3(cb) {
setTimeout(() => {
cb(3);
}, 3000);
}
asyncFunc1((result1) => {
asyncFunc2((result2) => {
asyncFunc3((result3) => {
console.log(result1 + result2 + result3);
});
});
});
In this example, the three async functions are called one after the other in a nested callback pattern, which can become difficult to read and understand as more functions are added.
5.Limited support for low-level operations: JavaScript is not a low-level language and it does not provide direct access to memory, disk, or other resources, which can make it less suitable for certain types of applications, such as operating systems or device drivers.
let buffer = new ArrayBuffer(1024);
let view = new DataView(buffer);
view.setInt32(0, 256, true);
console.log(view.getInt32(0, true)); // 0
In this example, JavaScript does not provide direct access to the memory, so it's not possible to get the value stored in the buffer.
6.Lack of type safety: JavaScript is a loosely typed language and it does not have strict type checking, which can make it easier to introduce bugs and make it harder to catch them during development.
7.Limited support for Object-Oriented programming: JavaScript's prototype-based model of OOP is different from traditional class-based OOP and it can make it harder to understand and maintain OOP code.
Top comments (10)
Concurrency is better handled using
asyncandawaitwhich are pretty powerful constructs for coding concurrent operations, and there's always promises which also stop the callback hell. Sure you can write code with callbacks if it helps with your particular architecture, but not a normal way these days.JavaScript has the whole Workers built in functionality which allows for using additional threads and can parallelize operations.
JavaScript has many powerful versions of object orientation, and includes classes, prototypes, mixins etc.
You are correct that the async and await constructs, as well as promises, provide a more readable and manageable way of handling concurrency in JavaScript. They make it easier to write and reason about asynchronous code and avoid the callback hell problem.
You are also correct that JavaScript has built-in functionality for using additional threads with Web Workers, which allows for parallelizing operations and improving performance.
And I agree that JavaScript has many powerful versions of object-oriented programming, such as classes, prototypes, and mixins, which provide different ways to structure and organize code. These features have been added to the language over time and make it more versatile and powerful. It's important to note that these constructs are not mutually exclusive and can be used together to create more robust and flexible objects.
Thank you for highlighting these points, I apologize for any confusion my previous responses may have caused.
I disagree with most of your points.
threads vs. single thread (points 1, 3, 4): js runtimes are single thread, but this is a objective statement, isn't better or worse than other architectures per se. This has strengths and weaknesses. It's important to understand this particular but isn't just "bad".
lack of type safety (point 6): if you need type checking try typescript in development. As most scripting languages (like python), js isn't strongly typed... which isn't a limitation. It's different. Adapt to the technology (or use ts)
Object-Oriented programming (point 7): again, this is an objective statement: js is oriented to Prototypes (instead to classes). I - personally - prefer prototype thinking to class thinking, IMO it's cleaner. For me this is a strong point. What I'm trying to say is that this is subjective: you can't declare that classes are "better" than "prototypes", it depends.
You are correct that the limitations I mentioned are not necessarily "bad", but rather are specific characteristics of the language that can have both advantages and disadvantages depending on the context and the use case.
Regarding the single threading, you're right that it has its own strengths and weaknesses, for example it simplifies the logic and avoids race conditions, but it can limit the performance when dealing with a lot of data or complex calculations.
Regarding the lack of type safety, you are correct that TypeScript can be used to add type checking to JavaScript, but it's worth noting that it is not native to the language, and thus, it's a limitation in that sense.
Regarding the Object-Oriented programming, you're right that JavaScript's prototype-based model of OOP is different from traditional class-based OOP and it can make it harder to understand and maintain OOP code for some developers, but it can also be seen as a strength by others who find it to be a cleaner way of thinking.
I apologize for any confusion , my intention was not to state that these limitations are inherently "bad", but to provide examples of some of the challenges that developers may encounter when working with JavaScript.
No need to apologise really 😅
We both agree js works different to Java 👌
I think javascript is really good at what it is supposed to do: web development. For type safety you get typescript and stuff like low-level operations is never necessary for a server. And btw, floating point errors are a common problem in every language due to the nature of how computers see numbers.
However, certain limitations do apply and that's why I prefer to use other languages for my backends (mostly Rails). Interesting article nonetheless!
I agree that JavaScript excels in web development and it's widely used for creating interactive user interfaces, single-page applications, and browser scripting.
You're also correct that the problem of floating-point errors is not unique to JavaScript, but it's a problem that affects many programming languages due to the nature of how computers represent numbers.
And you're right that certain limitations do apply, but they can be mitigated by using JavaScript together with other technologies such as TypeScript, WebAssembly, and Web Workers, and other languages like Ruby on Rails, Python, Java, etc. for the backend.
I'm glad you found the article interesting and I appreciate your feedback. Thank you for pointing out the limitations and strengths of JavaScript, and the context in which it excels.
Javascript definitely has some quirkyness. I feel like some points are not quite fair though. For example, points 6 and 7 are covered by Typescript which offers type safety as well as more advanced OOP features. Point 4 is a developer choice and infact many articles explain that writing nested callbacks is a bad practice and that you should use promises and async/await instead. Point 3 about multi-threading is a bit confusing. Javascript is a language that can run in several runtimes. In the browser it is limited to a single thread yes (although you have web workers), but the Node runtime for example is definitely multi-threaded.
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