using import and export in js code example

Example 1: js import and export

// helloworld.js

export function helloWorld() {
	return 'Hello World!';
}

// main.js

import helloWorld from './helloworld.js';

console.log(helloWorld());

Example 2: import and export type in js

// Exporting individual features
export let name1, name2, …, nameN; // also var, const
export let name1 = …, name2 = …, …, nameN; // also var, const
export function functionName(){...}
export class ClassName {...}

// Export list
export { name1, name2, …, nameN };

// Renaming exports
export { variable1 as name1, variable2 as name2, …, nameN };

// Exporting destructured assignments with renaming
export const { name1, name2: bar } = o;

// Default exports
export default expression;
export default function (…) { … } // also class, function*
export default function name1(…) { … } // also class, function*
export { name1 as default, … };

// Aggregating modules
export * from …; // does not set the default export
export * as name1 from …; // Draft ECMAScript® 2O21
export { name1, name2, …, nameN } from …;
export { import1 as name1, import2 as name2, …, nameN } from …;
export { default } from …;