10 Tips for Writing Clean and Efficient JavaScript Code published 3/14/2023 | 4 min read

JavaScript is widely used for developing web applications, and there is no denying that it is a powerful language. However, when it comes to coding in JavaScript, it is important to write clean and efficient code so that your web pages can load faster and run smoother.

In this article, we'll provide you with 10 tips for writing clean, efficient JavaScript code that will help make your web pages load faster, run smoother, and be easier to maintain.

1. Use Descriptive Names

When it comes to naming variables and functions, choose descriptive names. This will make your code more readable and easier to understand.

  
// Poorly named function
function a() {
   // code
}

// Well named function
function doSomething() {
   // code
}

2. Avoid Global Variables

Global variables can cause conflicts and make it difficult to debug code. Avoid using global variables wherever possible.

  
// Global Variable
let x = 5;

function doSomething() {
   // code
}

  
// Local Variable
function doSomething() {
   let x = 5;
   // code
}

3. Modularize Your Code

Divide your code into small, reusable modules. This will make your code more organized and easier to maintain.

  
// Poorly modularized code
function doSomething() {
   // code
}

function doAnotherThing() {
   // code
}

// Well modularized code
let module = (function() {
   function doSomething() {
      // code
   }

   function doAnotherThing() {
      // code
   }

   return {
      doSomething,
      doAnotherThing
   }
})();

4. Use Constants

Use constants instead of hardcoding values in your code. This will make your code more readable and easier to maintain.

  
// Hardcoded value
let x = 5;

function doSomething() {
   let y = x * 10;
   // code
}

  
// Constant value
const X = 5;

function doSomething() {
   let y = X * 10;
   // code
}

5. Optimize Loops

Loops can be performance-intensive, so it is important to optimize them whenever possible.

  
// Poorly optimized loop
for (let i = 0; i < array.length; i++) {
   // code
}

// Well optimized loop
let array = [1, 2, 3, 4, 5];

for (let i = 0, len = array.length; i < len; i++) {
   // code
}

6. Use Arrow Functions

Arrow functions are a shorthand way of writing functions in JavaScript. They make your code shorter and more readable.

  
// Regular function
function doSomething() {
   // code
}

// Arrow function
let doSomething = () => {
   // code
}

7. Use Default Parameters

Use default parameters to make your code more readable and reduce the number of lines of code.

  
// Without default parameter
function doSomething(x) {
   if (x == undefined) {
      x = 5;
   }
   // code
}

// With default parameter
function doSomething(x = 5) {
   // code
}

8. Use Destructuring

Destructuring is a way of extracting values from arrays and objects. It can make your code more readable and reduce the number of lines of code.

  
// Without destructuring
let arr = [1, 2, 3];
let x = arr[0];
let y = arr[1];
let z = arr[2];

// With destructuring
let [x, y, z] = [1, 2, 3];

9. Use Template Literals

Use template literals to make your code more readable and reduce the number of lines of code.

  
// Without template literals
let str = "The answer is " + x + ".";

// With template literals
let str = `The answer is ${x}.`;

10. Use let and const instead of var

Use let and const instead of var. This will make your code more readable and easier to maintain.

  
// var
var x = 5;

// let
let x = 5;

// const
const x = 5;

Implement these tips in your JavaScript code to make it more efficient, readable, and maintainable. Happy coding!