In today’s time, one of the most important things to consider while developing an application or a webpage is its performance. No business owner would like to have an application that crashes frequently or doesn’t load properly. Because if the application or website doesn’t perform correctly, then the user waiting time will increase which can lead to loss of potential clients. As per the survey by Kissmetrics, around 47% of visitors expect a website to load in a minimum of 2 seconds, and they leave the website if it takes a longer load.

To offer quick and better performance, the majority of app development companies are using JavaScript for creating amazing applications. But not every JavaScript developer can code so efficiently and that is why, in this blog, we are going to discuss some of the major tips that can help them code well and improve application performance.

Top 9 Tips to Write Efficient JavaScript Code

Some of the best tips that every JavaScript developer can use while coding an efficient web page or application -

1. Define the Execution Context

When the developer wants to effectively measure any improvements that they have incorporated into the program, they must establish a perfectly well-defined environment where they can test the code’s performance.

When the development team is trying to do performance testing and optimizing for all versions of all Javascript engines, it might not always be feasible in practice. But, doing testing in every single environment is not a good practice as it can only offer you partial results. Therefore, it is the best idea to establish multiple well-defined environments and later test its code to see if it works.

2. Cache in the Browser

One of the best options to improve JavaScript performance requires two different ways. The first way is to make use of the JavaScript Cache API, which the developer can use by installing a service worker. Besides this, the second way is to use the HTTP protocol cache. Developers generally use the coding scripts to access a certain object. And by storing all the repeated access objects into a user-defined variable and using a variable in proper references to that object, the development team can improve the performance immediately.

3. Remove Unused JavaScript

Removing unused JavaScript code is one of the most essential steps. It doesn’t only allow the developers to reduce transmission time but also helps in reducing the time it takes for the browser to compile and analyze the code. And to do this, the JavaScript development team has to take into account a few points. And they are as follows -

• If any functionality is not being used by the users, removing it is the best option.
• Sometimes it happens that the developer mistakenly includes a library that is not at all necessary. So removing such a library that isn’t useful for functionality is feasible.

4. Put Off the Unnecessary Load of JavaScript

Every application or website user wants to see a page load as quickly as possible. But it is not always possible that all the functions of the website are available on the first load of the webpage. And if the user wants to perform any kind of action to execute a function, it is possible to cut off the loading time of the function until the initial page load.

In this way, the developer can easily avoid loading and compiling JavaScript code that is the reason behind delaying the initial display of the webpage. So, once the webpage is fully loaded, the development team starts the loading of all the functionalities so that they are immediately available for the users. As per Google’s RAIL model, the deferred load can be done in blocks of 50ms and the reason behind it is that it does not influence the interactions of user’s with the webpage.

5. Avoid Using More Memory

One thing to do for improving the JavaScript performance is to limit the usage of the memory. Only the necessary memory must be used as this can allow one to know how much memory a device requires to run the business application. This is the practice that every business owner should ask their JavaScript development teams to do.

The main reason to follow this practice is that, whenever the code requests the browser, it reserves new memory and it executes the browser’s garbage collector which eventually stops JavaScript. And if this happens frequently, the webpage will start working slowly.

6. Avoid Memory Leaks

If the website developed by the team has an ongoing memory leak, then the loaded page will reserve more and more memory. This can eventually occupy all the available memory of the device and can also impact the performance. This generally happens to web pages that have a carousel or image slider.

To overcome this issue, the JavaScript developers use the Chrome Dev Tools. It helps in analyzing if the website has memory leaks or not by recording a timeline in the webpage performance tab. Generally, the generation of memory leaks is from pieces of the DOM that the developers removed from the page. Besides, it can even be from the variable that makes reference to leaks and this is the reason why the garbage collector can not remove them.

7. Save Frequent Access of DOM to a Local Variable

Generally, accessing the DOM is a very slow process. So, if the developer needs to read the content of the elements more than usual, then it is a better option to save it in a local variable. But when the JavaScript development company decides to do that, one thing that it needs to consider is that, if it will later remove the value of the DOM, the variable must be set as “null”. By doing so, one can save the application or website from memory leaks.

8. Use Web Workers to Execute Code for Longer Time

As per documentation by the Mozilla Developers Network (MDN), the Web Workers can easily run a script operation in a background thread and they can keep it separate from the main execution thread of a web app. The advantage of this method is that a high level of processing can be carried out in a separate thread. This also allows the main thread to run without being slowed down.

Basically, the web workers allow the code to perform processor-intensive calculations and that too without blocking the UI thread. Besides this, with the help of web workers, a development company can spawn new threads and assign work to these threads to get efficient performance.

9. Prioritize Access to Local Variables

Generally, when it comes to JavaScript coding, it first searches to see if a variable is locally available or not. Then it searches in higher levels of scope which is till the global variables. When the developer saves the variables in a local scope, JavaScript can access them much faster. Therefore, the local variables are based on the most essential scope and it has the capability to pass multiple levels of scope.

Besides this, when it comes to defining the function scope without a preceding variable declaration within a local variable, it becomes important to precede each variable. This variable can be preceded with let or const so that it can define the current scope in order and help in preventing the look-up and can speed up the JavaScript code.

Conclusion

As seen in this blog, by following specific tips of techniques, any JavaScript development company can improve JavaScript performance. These techniques can also offer superior JavaScript development services. So, if any company implements them together for their own or client’s application, they can observe a huge improvement in the app speed. If you are confused with the thought of choosing the best software outsourcing company then there are a few companies that can be the make-or-break point for your business if you choose them wisely.