4 JavaScript Code Optimization Tips for Front-End Developer

JavaScript has become one of the most popular programming languages of all time. It is used by almost 96% of websites all over the world according to W3Tech. One key fact you should know about the web is that you have no control over the hardware specifications of the devices your user would access your website on. The end-user may access your website on a high-end or a low-end device with either great or poor internet connection. This means that you have to make sure your website is optimized as much as possible for you to be able to satisfy the requirements of any user.

 

1-Define Variables Locally

Whenever you call a certain function, the variables that are used to define that function are stored inside. Variables can be categorized into two types.

Local variable: – Variables that are defined only within themselves.

Global variable: – Variables that are used throughout the script.

At the time when you’re calling a function, the browser does an activity which is termed as scope lookup. With the increase in the number of scopes in the scope chain, there’s also an increase in the amount of time taken to access variables that are outside the current scope.

2-Remove Unused Code and Features

Sometimes, you might include features that are not used at all. It is better to keep this extra code only in the development environment, and not to push it for production so that you would not burden the client’s browser with unused code.

You can remove unused code manually or by using tools such as Uglify or Google’s Closure Compiler. You can even use a technique called tree shaking which removes unused code from your application.

 

3-Keep codes light and small

While you’re in a development stage, you must ask yourself these questions below.

Do I really need this module?

Can I do this in a simpler manner?

Why am I using this framework?

Is this worth the overhead?

4. Avoid Memory Leaks

Even though garbage collection is performed automatically in JavaScript, there can be certain instances where it will not be perfect. In JavaScript ES6, Map and Set were introduced with their “weaker” siblings. This “weaker” counterpart known as WeakMap and WeakSet hold “weak” references to objects. They enable unreferenced values to be garbage collected and thereby prevent memory leaks. You can read more about WeakMaps.