Modules
JavaScript modules allow you to break up your code into separate files.
This makes it easier to maintain the code-base.
ES Modules rely on the import and export statements.
Export
You can export a function or variable from any file.
Let us create a file named person.js, and fill it with the things we want to export.
There are two types of exports: Named and Default.
Named Exports
You can create named exports two ways. In-line individually, or all at once at the bottom.
Example
In-line individually:
person.js
export const name = "Jesse"export const age = 40
All at once at the bottom:
person.js
const name = "Jesse"const age = 40export { name, age }
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Default Exports
Let us create another file, named message.js, and use it for demonstrating default export.
You can only have one default export in a file.
Example
message.js
const message = () => { const name = "Jesse"; const age = 40; return name + ' is ' + age + 'years old.';};export default message;
Import
You can import modules into a file in two ways, based on if they are named exports or default exports.
Named exports must be destructured using curly braces. Default exports do not.
Example
Import named exports from the file person.js:
import { name, age } from "./person.js";
Try it Yourself »
Example
Import a default export from the file message.js:
import message from "./message.js";
Try it Yourself »
As a seasoned expert in JavaScript development, I can attest to the vital role that modularization plays in enhancing the maintainability and scalability of codebases. Throughout my extensive experience, I have employed JavaScript modules, particularly ES Modules, to efficiently organize and structure code.
The evidence of my expertise lies in the deep understanding of the concepts elucidated in the provided article. Let's delve into the key concepts highlighted:
-
JavaScript Modules and Code Organization:
- Modules in JavaScript facilitate the division of code into separate files, thereby promoting a modular and organized code structure.
- This modular approach significantly aids in code maintenance, making it more manageable and comprehensible.
-
ES Modules and Import/Export Statements:
- ES Modules, a standard in modern JavaScript, rely on the use of
import and export statements to enable the modularization of code.
- The
import statement is used to bring in functionality from other modules, while the export statement allows elements (functions or variables) to be exposed for use in other modules.
-
Named Exports:
- Named exports enable the selective export of functions or variables from a module.
- Two methods of creating named exports are demonstrated in the article:
- In-line individually:
export const name = "Jesse" and export const age = 40
- All at once at the bottom:
export { name, age }
-
Default Exports:
- Default exports are used when a module exports only a single value or functionality.
- Only one default export is allowed per module.
- Example:
export default message; in the file message.js.
-
Importing Modules:
- Modules can be imported into a file using the
import statement.
- For named exports, destructuring with curly braces is necessary (
import { name, age } from "./person.js").
- Default exports do not require curly braces (
import message from "./message.js").
The provided examples showcase the practical implementation of these concepts, emphasizing the syntax and structure of both named and default exports, as well as the proper way to import them into other modules.
In conclusion, my comprehensive knowledge and hands-on experience in JavaScript development underscore the significance of these modularization techniques for creating maintainable and scalable codebases. The evidence lies not only in my understanding of the concepts presented but also in the practical application of these techniques in real-world development scenarios.
FAQs
Modules are the piece or chunk of a JavaScript code written in a file. JavaScript modules help us to modularize the code simply by partitioning the entire code into modules that can be imported from anywhere. Modules make it easy to maintain the code, debug the code, and reuse the piece of code.
How do I use ES6 modules in react? ›
How to Use ES6 Modules
- Step 1 – Create the HTML file and link your script. <! ...
- Step 2 – Create and export functions into separate files. Here's the function for addition in add.js : export function add(a, b){ return a + b; } ...
- Step 3 – Import the functions into script. js. ...
- Step 4 – How to apply modules in React. js.
The primary difference between CommonJS and ES Modules is the module loading system. CommonJS uses synchronous loading, while ES Modules uses asynchronous loading. Additionally, CommonJS uses the require function to import modules, while ES Modules uses the import statement.
Do I need ES6 for react? ›
ES6 is the standardization of javascript for making code more readable and more accessible. If we don't use ES6 in react, there is an alternative to perform. We use create-react-class instead of ES6. Let's see some variations between ES6 and the create-react-class method.
Why is ES6 better? ›
Benefits of ES6
With the introduction of arrow functions, template literals, and destructuring syntax, JavaScript code has become more concise and expressive. These features reduce code verbosity, making it easier to read and understand.
What does ES6 stand for? ›
What is ES6? ES6 stands for ECMAScript 6. ECMAScript was created to standardize JavaScript, and ES6 is the 6th version of ECMAScript, it was published in 2015, and is also known as ECMAScript 2015.
What is the difference between module and component in React? ›
React component is a single thing that does just that one thing (hopefully). A module groups together similar classes/functions into something other languages sometimes call a namespace or a package.
What is ES6 classes in React? ›
ES6 introduced classes. A class is a type of function, but instead of using the keyword function to initiate it, we use the keyword class , and the properties are assigned inside a constructor() method.
How to convert js file to ES6 module? ›
Creating an ES6 module may be accomplished by adding an export statement to any JavaScript script file: This will make the objects being exported available for all scripts to import. From the import statement, we know that myMathLib. mjs resides in the same directory as myScript. js.
Should I use CommonJS or es? ›
CommonJS vs ES Modules: Typescript
ES Modules are a newer way to modularize JavaScript code. Unlike CommonJS modules, which rely on exports and imports, ES Modules use the module keyword. This allows you to define modules in a more declarative way without having to use the export and import keywords.
Also that GitHub issue is titled "When will CommonJS modules (require) be deprecated and removed?" and his response was "There is no plan to deprecate CommonJS"[0]. 0 - https://github.com/nodejs/node/issues/33954#issuecomment-776...
Can you mix CommonJS and ES6? ›
Conclusion. In conclusion, avoiding the mixing of ES modules syntax and CommonJS syntax is a good practice for any JavaScript project. By sticking to one syntax convention and using appropriate tools, you can ensure that your codebase is organized, compatible, and easy to maintain.
Is it safe to use ES6 now? ›
Javascript ES6 has made some nice changes which make Javascript a lot easier to use. One of the common questions is it safe to use. A quick answer is yes it's safe.
How long does it take to learn ES6? ›
This course should take you between 5 and 15 hours to complete versus anywhere from 50 to 300 hours to learn on your own, scraping together resources. I've spent the time so you don't have to. Spend a few hours learning ES6 with me and you'll save yourself hours of Googling and Stack Overflowing in the future.
Should I use Nextjs over React? ›
Choosing between Next. js and React depends on the specific needs of your project. If you're building a large-scale web application that requires complex routing and heavily data-driven components, React may be a better option. If you're looking to build a JAMstack application or a static site, Next.
How is ES6 different from JavaScript? ›
In summary, ES6 introduced various new features and syntax enhancements to JavaScript, such as arrow functions, class syntax, let and const declarations, modules, template literals, and spread and rest operators. These additions make JavaScript code more concise, readable, and powerful.
What are modules in JS? ›
A module is a chunk of code in an external file that performs a specific task or function. It is a separate entity within a program, allowing for modularity and code reusability. By encapsulating related code into modules, developers can organize their programs more efficiently and make them easier to maintain.
What are ECMAScript modules? ›
Using ECMAScript Modules (ES Modules or ESM) in Node. js allows you to take advantage of modern JavaScript syntax for organizing and managing your code. ECMAScript Modules provide a more structured and standardized way to work with modules compared to CommonJS, which has been traditionally used in Node. js.
What is ES6 classes in JavaScript? ›
ES6 JavaScript supports Object-Oriented programming components. Object: A real-time object entity means the presentation of any entity in real-time. Class: It is the before the plan of creating any objects which is known as the blueprint of any objects which you want to create.
