There are a lot of different aspects to being a good JavaScript developer. However, we believe that five advanced concepts set the best developers apart. If you want to be a top JavaScript developer, master these concepts.
1. Prototype Chain
If you’re serious about becoming a better JavaScript developer, you need to understand the prototype chain. In JavaScript, all objects inherit from the ObjectPrototype. This includes things created from custom constructors, like new Person().
The prototype chain is important for two reasons: performance and inheritance.
When you access a property on an object, the JavaScript engine first looks for that property on the Object itself. If it can’t find it, it looks up the prototype chain until it finds the property or reaches the end of the chain.
If you’re constantly accessing properties on an object, it’s important to make sure they’re as close to the Object as possible so the engine doesn’t have to search the prototype chain.
Inheritance is when an object can inherit properties and methods from another object. In JavaScript, this is done by setting the prototype property of a constructor function to another object.
For example, let’s say you have a Person constructor function:
function Person(name) {
this.name = name;
}
You can set the prototype property to a new instance of Person:
Person.prototype = new Person(“John”);
Any objects created with the Person constructor will access the name property.
This is a compelling feature of the prototype chain, which makes JavaScript object-oriented programming possible.
2. Asynchronous Programming
You know that async programming can be a challenge if you’re a JavaScript developer. There are so many different ways to do it, and it can be tough to keep track of all the different options. But don’t worry – we’re here to help.
This blog post will explore some advanced JavaScript concepts that will make you a better async programmer.
First, let’s talk about promises. A promise is an object that represents the result of an asynchronous operation. Promises can be either resolved or rejected, and they can be chained together to create complex async programs.
Once you understand how promises work, you’ll be able to use them to write cleaner and more efficient async code.
Next, let’s talk about async/await. Async/await is a new way to write async code in JavaScript. It’s built on top of promises, making async code look and feel like synchronous code. If you’re not familiar with async/await, you should check out our Async/Await tutorial.
Finally, let’s talk about some advanced concepts that will make you a better async programmer. One of these concepts is error handling. When working with async code, it’s important to handle errors correctly. Otherwise, your program may end up in a broken state.
Another advanced concept is performance. When you are working with async code, you need to be aware of how your code impacts your program’s performance. Otherwise, you may end up with a program that runs slowly or even crashes.
3. event Handling
Another important aspect of JavaScript is event handling. This is how you respond to user input and other events in the browser. Event handling is important for creating interactive applications.
You need to know a few things to master event handling.
First, you need to understand the difference between event handlers and event listeners. Event handlers are functions that are attached to elements, and they get executed when an event is triggered. On the other hand, event listeners are functions that listen for events and take action when they occur.
Second, you need to understand how to use the event object. An event object is an object that contains information about the event that just occurred. It’s important to know how to access this Object to get information about the event, such as the target element, the type of event, and any other relevant data.
Finally, you need to know how to use event delegation. This technique allows you to add event listeners to parent elements and then has those listeners handle events for all child elements. This is valid for situations where you have a lot of elements that need to be handled in the same way.
If you can master these three concepts, you’ll be well to become a great JavaScript developer. So study up and start practicing!
4. Error Handling
As a JavaScript developer, it’s important to have a strong understanding of error handling. This helps you write code that is more robust and can better handle unexpected situations.
A few advanced concepts can help you become a better error handler. First, let’s take a look at the try/catch/finally construct. This is a powerful tool that can be used to handle errors in your code.
The try block contains the code that may generate an error. The catch block contains the code that will be executed if an error occurs. The final block contains code that will always be executed, whether or not an error occurs.
This construct can be very useful for handling errors. For example, you can use it to gracefully handle an error that may occur when a user tries to access a resource that doesn’t exist.
Another concept that can be helpful is exception handling. This allows you to handle errors in a more organized and structured way.
With exception handling, you can define a custom error handler that can deal with errors in your code. This can be very helpful in situations where you want to handle errors specifically.
Exception handling is a powerful tool that can help you write better code. However, it’s important to use it to be consistent with the rest of your code. Otherwise, it can make your code more difficult to understand and maintain.
Finally, one last concept that can help you with error handling is an early return. This means that you return from a function as soon as an error occurs.
Early return can be very helpful in situations where you want to handle an error and then stop the function’s execution. This can help prevent the function from continuing to execute if there is a problem.
Error handling is a critical skill for JavaScript developers. These concepts can help you write code that is more robust and better able to handle unexpected situations.
5. Performance
As a JavaScript developer, it’s important to understand the language’s core concepts. But beyond that, there are a few advanced concepts that can help you take your skills to the next level. In this blog post, we’ll explore three of those concepts and how they can help you write better code with better performance.
The first concept is closures. A closure is a function that has access to the external scope variables, even after the outer scope has been executed. This can be really powerful because it allows you to create functions that can maintain the state. For example, you could use a closure to create a function that increments a counter every time it’s called.
The second concept is prototype-based inheritance. In JavaScript, objects can inherit from other objects. This works because an object has a prototype, which is another object that can inherit properties. So, if you have a `superclass` object and a `subclass` object, the `subclass` can inherit properties from the `superclass.`
The third and final concept is async/await. This is a relatively new feature of JavaScript, but it’s already revolutionizing how asynchronous code is written. Async/await allows you to write asynchronous code that looks and feels like synchronous code. This makes it much easier to reason about, making your code a lot more performant.
That’s it for now! If you understand these three concepts, you’re well to become a better JavaScript developer.