What is importing and exporting in React JS? (2024)

FAQs

What is importing and exporting in React JS? ›

React Importing and Exporting Components are two major operations that enable the re-use of the components to create a collection of components and hence a complete application.

Importing allows using contents from another file, whereas exporting makes the file contents eligible for importing.

The export declaration is used to export values from a JavaScript module. Exported values can then be imported into other programs with the import declaration or dynamic import.

A: We need to import React in every component file because React provides the necessary functions and objects required to create and manage components. By importing React, we're telling our code to make use of these functions and objects, allowing us to build our components.

import { useState, useEffect } from 'react'; I prefer the first as it doesn't pollute the namespace and makes it clear which package a function is coming from where it is called (useful when you have functions with the same name in multiple packages).

Selling of goods and services from the home country to a foreign country is known as export, while buying of goods and services and bringing them into one's home country is known as import. The import and export of goods can be done either directly or indirectly.

The export keyword allows these elements to be used in other JavaScript files, thus making the code reusable and modular. There are two main types of export in React: named export and default export.

Exports are goods that are sold in a foreign market, while imports are foreign goods that are purchased in a domestic market. Exports and imports are important for the development and growth of national economies because not all countries have the resources and skills required to produce certain goods and services.

In a module, there can be classes, functions, variables, and objects as well. To make all these available in another file, we can use export and import. The export and import are the keywords used for exporting and importing one or more members in a module.

IEC or Importer Exporter Code is a unique 10-digit alpha numeric code issued on the basis of PAN of an entity. Question: Why is IEC required? To import or export in India, IEC Code is mandatory. No person or entity shall make any Import or Export without IEC Code Number, unless specifically exempted.

How to import functions in React JS? ›

Importing a Function

Importing is like telling ReactJS, "Hey, I need this function from that file". Here's how you import a function: // File: App. js import { sayHello } from './MyFunctions'; // Now you can call sayHello in this file sayHello(); // prints "Hello, world!"

React-script-tag

This is the easiest way of loading JS files for a beginner. React-script-tag is an npm package that provides a React <script> tag that supports universal rendering. All standard <script> attributes like async , src , type , and defer are supported, including onLoad and onError callbacks.

Importing a Class in ReactJS

This is similar to borrowing a book from a library. You don't own the book, but you can use it wherever you want, till you return it. Here's how you can import a class in ReactJS: import HelloWorld from './HelloWorld';

Exporting Function Components in React

Here's how we can do it: function Welcome(props) { return <h1>Hello, {props.name}</h1>; } export default Welcome; In this code, export default Welcome; is making the Welcome function accessible to other modules.

In summary, named exports are useful when you want to export multiple values and import them with their specific names, while default exports are handy for exporting a single value and giving it a custom name when importing. The choice between the two depends on the structure and requirements of your codebase.

The default export is also used for exporting components, values, classes, etc. in React JS, but only one element can be exported to another component at a time as a default export. In other words, a file can have only one default export.

Understanding Data Import and Export

Data import refers to the process of bringing data into a system or application from an external source. Conversely, data export involves transferring data from a system or application to an external destination.

With import , developers can break a program into manageable modules and consolidate the pieces as needed. A developer can use a code module in more than one project, sometimes as part of a library of frequently re-used utilities or shared functionality.

Other file types can't be imported with these statements. These are only prioritized in ES modules where its specifier can only be a URL-style relative path or a package name. But export statements permit the user to export its created objects and methods to other programs.