JavaScript is a popular scripting language that is used on millions of websites and isn’t going away anytime soon. HTML and CSS give web pages style, but it’s JavaScript’s magic that brings them to life. Javascript can be used with a variety of frameworks and packages. Many concepts are complex and intimidating to developers, but having a firm grasp on them will pay off in the long run. So, in today’s blog, we’ll go through the top six javascript concepts that everyone should know.
- Hosting: When developers are inexperienced with the concept of hoisting in javascript, unexpected results can occur. In javascript, you can call a function before it is defined and avoid the ‘Uncaught ReferenceError’ error. Hoisting is the result of the javascript interpreter moving variables and function declarations to the top of the current scope (function scope or global scope) before executing the code.
- IIFE: As the name implies, an IIFE (Immediately Invoked Function Expression) is a javascript function that is invoked. Variables defined within the IIFE are inaccessible to the outside world, preventing contamination of the global scope. The major reason for using IIFE is to run code rapidly while maintaining data privacy.
- Scope: Scope is a term that relates to variable access. What variables do I have access to when a program is running? In javascript, you’re always in the root scope, which is the window scope. The scope, which is merely a box with a boundary, contains variables, functions, and objects. Variables are restricted by certain limits, which impact whether or not you have access to them. It limits the visibility or availability of a variable to other portions of the code. This concept must be fully grasped because it aids in the separation of logic in your code and improves readability.
- Closures: A closure is a function that runs inside another and has access to the variables of the outer function. While this definition appears to be straightforward, the scope is where the real magic occurs. The inner function has access to the variables declared in its scope (variables defined within curly brackets), the scope of its parent function, and the global variables (closure). It’s important to remember that at this time, the outer function can’t access the inner function variable.
- Callbacks: In javascript, a callback is a function that is passed as a parameter to another function and then called or executed within that function. A function must wait for another function to complete or return a value in this situation, resulting in a functional chain (when X is completed, then Y is executed, and it goes on.). This is why callback is widely used to offer synchronous functionality in javascript’s asynchronous actions.
- Promises: We know what a callback is, but what if your code includes callbacks within callbacks, and so on? Known as ‘callback hell,’ this recursive callback structure claims to assist solve this problem. Promises come in helpful when we need to do two or more back-to-back operations (or chaining callbacks) with asynchronous javascript. A promise is an object with the capability of generating a single value in the future, either a resolved value or an explanation of why it hasn’t been resolved yet (rejected). The problem of ‘callback hell,’ which is nothing more than a recursive callback structure, is solved by promises.
Final Thoughts: You can learn more about Javascript from blogs, video tutorials, and other resources. The good news is that there are numerous free resources available on the internet. Our advice is to learn from youtube. It’s fun and entertaining. There are plenty of videos on Youtube if you search “javascript concepts.” The only problem is that you have no idea which video to select. And the one you select might not be the right one for you.
To fix that difficulty, we have something for you. Learning effectively is now easier than ever with online learning, especially when there are online learning platforms like LearnTube which presents you with the top most curated content. Sign-up to LearnTube, select your course, and start learning!
