JavaScript - export statement

In this article, we would like to show you how to use the export statement in JavaScript.

Description

The export statement is used when creating modules that can be used by other programs with the import statement. There are two different types of export, named and default. You can have multiple named exports per module but only one default export.

Syntax

Named exports:

// export features declared earlier
export { myFunction, myVariable };

// export individual features such as variables, constants, functions, classes
export let myVariable = 3;
export function myFunction() { /* ... */ };

Default exports:

// export feature declared earlier
export { myFunction as default };

// export individual features
export default function () { /* ... */ }
export default class { /* ... */ }

Note:

Each subsequent export overwrites the previous one.

Practical examples

Example 1 - using named exports

module.js file:

function myFunction() {
  console.log('My function text');
}

const myConstant = 1;

var myObject = {
  id: 1,
  color: 'red',
};

export { myFunction, myConstant, myObject };

index.js file:

import { myFunction, myConstant, myObject } from './module.js';

myFunction();                // My function text
console.log(myConstant);     // 1
console.log(myObject.color); // red

Output after running index.js under Node.js:

My function text
1
red

Example 2 - using default exports

module.js file:

export default function myFunction() {
  console.log('My function text');
}

index.js file:

import myFunction from './module.js';

myFunction(); // My function text

Output after running index.js under Node.js:

My function text

References

1. export - JavaScript | MDN