Top JavaScript Best Practices and Standards to Know

JavaScript is a popular programming language that is widely used for building web applications. It is a powerful and flexible language that can be used to create a wide variety of applications, from simple scripts to complex programs. Some common practices for writing JavaScript code −

Name things by their name. It is easy because they are short and easy to read.

Avoid using global variables. These are general variables in a program. It is tough to understand what is happening in the code. It also leads to problems when the code is changed.

Coding style is significant so that your code looks tidy. Follow a specific technique to make sure everything looks the same.

Don't mix different technologies. It can cause problems. Use shortcut notation when it makes sense. Taking care of one specific task at a time will make it easier for you.

Avoid heavy nesting. There are some things you can do to make the loop run faster. It means the program will do more in a shorter amount of time.

Don't let access your DOM (Document Object Model) too much. If you want to add extra functionality to your web page, you can use JavaScript. It won't take up too much space on the page, so you'll be able to add more content without worry.

People who have done great things before us can help us to achieve our goals.

Specific Best Practices

Whenever you want to use a local variable in your code, you should first declare it. It lets the computer know that you're using this variable in this particular spot in your program.

The declarations on top are significant. They show what the content of the document is.

First, we need to set some variables. These will help us remember what we are doing.

  • Declare Objects with const.

  • A const array is a type of array that can only hold constant values.

  • Don't create a new object with the object's existing constructor new Object()

  • Avoid Automatic Type Conversions at all costs.

  • Utilize strict equality (===) Comparation.

  • Utilize the parameter defaults.

  • Use Defaults to End Your Switches.

  • Don't use objects that are a number, string, or boolean.

  • Don't use eval.

  • Consider the use of let and const.

We can define local variables that have their block-specific scope by using the let keyword. We can define local block-scoped variables using the const keyword that have a fixed value. When declaring your variables, utilize the let and const keywords when applicable. The const keyword only prevents reassignment, so keep that in mind. The variable is not become immutable by this.

Use Regex

Regex is an incredibly effective and enjoyable tool when extracting or working with strings. Use Regex instead of indexOf() and substring() when performing complex string searches and manipulations.

You may find intricate patterns using regular expressions, then change or extract text that matches those patterns.

Always keep the Future in Mind

What if you need to add more commands to this if statement in the future? You would have to change this section of code to accomplish that.

Apply JSLint

Debugger JSLint creator is Douglas Crockford. Just put your script into the box provided, and the program will rapidly check it for any obvious bugs and problems.

Scripts Should be at the Bottom of the Page

Note that the main objective is to make the user's experience as seamless as possible. The browser must wait to load the script until the file loads. As a result, the user will have to wait longer to see any advancement.

Place JS files towards the bottom, right before the closing body tag, if their sole duty is to add functionality, such as after a button click. Unquestionably, this is a best practice.

Declare Variables Outside of the "for" Statement

Avoid making the JavaScript engine work harder than necessary while performing long-for statements.

Describe Your Code

At first glance, it can appear needless, but you want to comment on your code thoroughly. What happens to the project months later, and you realize that you can't immediately recall your logic? How would you feel if one of your coworkers needed to change your code? Comment on essential code portions always.

Use {} as Opposed to New Object ()

In JavaScript, there are numerous ways to build objects. The new function Object() { [native code] } might be a more conventional approach.

This approach, however, is marked as "poor practice." It is a little out of the ordinary, but it isn't dangerous. We advise using the 'object literal' technique instead.

Take Caution When Making for-in Statements

You might discover that you also receive method functions or other inherited properties when iterating through the components in an object. Always encapsulate your code in an if statement that filters with function hasOwnProperty() { [native code] } to get around this.

Self-Executing Procedures

Calling a function automatically without invoking it through code is easy. Just enclose your JavaScript function in parentheses, followed by an additional set that serves as a callback for the JavaScript function.

Always Quicker to use raw JavaScript than a Library

JavaScript libraries like jQuery and lodash can help you code much faster, especially when working with AJAX. But still, remember that a library will never be as quick as pure JavaScript.

Although the each() method of jQuery is excellent for looping, a native for statement will always be somewhat quicker.

Employ Arrow Functions

Arrow functions, a recent addition to JavaScript, are a further crucial feature. They offer a wide range of advantages. Firstly, they make the functional parts of JavaScript easier to write and more aesthetically pleasing.

Parallel Promise Execution

It is best to execute your asynchronous operations concurrently because this will speed up and improve the responsiveness of your app. Just wrap your tasks with 'Promise.all' and run them together if they don't depend on one another's results.

Place JavaScript Separately

Add JavaScript in a separate file to improve code readability.


This tutorial discussed whether there are any standards or best practices for JavaScript. Certainly, there are many standards for working with JavaScript. We suggest you follow all these best practices in your JavaScript projects.