5 Most Common Mistakes Made by JavaScript Developers

Javascript Development

JavaScript is the base language for virtually all the modern day web applications. In the past few years, we have seen an increase in the overall number of powerful JavaScript-based libraries and frameworks in building web applications. This worked for Single Page Applications as well as server-side JavaScript platforms. JavaScript has definitely become omnipresent in the world of web development. This is why it is a major skill that should be mastered by web developers.

JavaScript might look really simple in the first look. Though building basic JavaScript functionality is really a simple and straight process for anyone, even if the person is completely new to JavaScript. But the language is still more complex and powerful than we would actually like to believe. You can learn a lot of things in JavaScript classes by ECMAScript 2015. These help in writing enjoyable code and also addresses inheritance issues. These simple things can lead to complex issues at times. Let’s discuss some of the most common problems.

  1. Block-level scope – One of the most common misunderstandings among JavaScript developers is to think that it offers a new scope for each code block. This could be true for several other languages, but not completely true for JavaScript. Though block-level scopes are getting further support by the way of new keywords which will official keywords in the ECMAScript 6.
  2. Memory Leaks – If you are not attentive enough, a memory leak is something that is unavoidable while coding for JavaScript. There are many ways in which memory leaks can occur. One major memory leak happens when you have loose references to defunct objects. The second memory leak would happen when there is a circular reference. But there are ways to avoid this memory leak. Global Variables and objects in the current call stack are known as roots and are reachable. They are kept in memory for as long as they can be easily accessed from roots using a reference.
  3. DOM Manipulation – You can very easily manipulate DOM in JavaScript, but there is no way this can actually be done efficiently. The addition of a DOM element to code is an expensive process. The code that is used to add multiple DOMs is not efficient enough and thus it will not work well. This is where you can use document fragments which can help in improving both efficiency and performance.
  4. Referencing – The coding techniques and design patterns of JavaScript have become advanced in the last few years. This has lead to an increase in the growth of self-referencing scopes. These scopes are a very common cause of confusion for this/that. A compliant solution for this problem is to save your reference as this in a variable.
  5. Strict Mode – The Strict Mode is a process in which the error handling on your JavaScript runtime is made stricter and this makes it even more secure. The use of Strict Mode has been accepted widely and made popular. The omission of it is considered as a negative point. The major benefits of strict mode are easier debugging, accidental globals are prevented, duplicate property names are rejected etc.
  6. Subclass Issues – In order to create a class into a subclass of another class, you will be required to use the extends keyword. You will have to first use super(), in case a constructor method has been applied in the subclass. This shall be done before using this keyword. If this is not done, the code will not work. If you keep allowing JavaScript classes to extend regular objects, you will keep finding errors.


In the case of JavaScript and similarly any other language, the more you try to understand how it works and how it doesn’t work, it will be easier for you to build a solid code. This will allow you to take proper advantage of the language. The lack of proper understanding is where the problem begins. The ES6 classes of JavaScript provide you with tips to create object-oriented code.

If you don’t clearly understand the smaller twists and turns in the code, you will end up with bugs in your application. If you have doubts, you can consult other full-stack web developers.

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