Last Updated : 19 Aug, 2024
Node’s require is CommonJS-based and loads modules synchronously, while ES6 import/export is part of the ECMAScript standard, allowing asynchronous, statically-analyzed module loading.
Table of Content
- Require
- Difference between node.js require and ES6 import and export:
- Conclusion
Require
The built-in require function in Node facilitates the inclusion of modules from separate files, allowing the integration of core Node modules, community-based modules (node_modules), and local modules in a program. Primarily used for reading and executing JavaScript files, it returns the export object. Notable inbuilt modules include HTTP module, URL, query string, path, and others.
Syntax:
const express = require('express');- To include the local module is as follows. For an instance, you require ‘abc’ module, without specifying a path.
require('abc');Example: Node will look for abc.js in all the paths specified by module.paths in order.
require('abc');Output:
- If node can’t find it:
Error: Cannot find module 'abc'
at Function.Module._resolveFilename (module.js:470:15)
at Function.Module._load (module.js:418:25)
at Module.require (module.js:498:17)
at require (internal/module.js:20:19)
at repl:1:1
at ContextifyScript.Script.runInThisContext (vm.js:23:33)
at REPLServer.defaultEval (repl.js:336:29)
at bound (domain.js:280:14)
at REPLServer.runBound [as eval] (domain.js:293:12)
at REPLServer.onLine (repl.js:533:10)
- If node find it:
// It is the content of the file
Geeksforgeeks example for require
Features:
- Synchronous loading of modules.
- Can load JSON files, native Node.js modules, or custom modules.
- Allows for conditional and dynamic imports.
ES6 Import & Export
ES6 Import and Export statements are used to refer to an ES module. Other file types can’t be imported with these statements. They are permitted only in ES modules and the specifier of this statement can either be a URL-style relative path or a package name.
Whereas Export statements allow the user to export his created objects and methods to other programs. For instance, if you assign a string literal then it will expose that string literal as a module.
Syntax:
- For importing file.
// Importing submodule from
// 'es-module-package/private-module.js';
import './private-module.js';
- For exporting file.
module.exports = 'A Computer Science Portal';Example: Create two JS file one is for importing and another one is for exporting or you can use any module to import so export one will not be required.
// Exporting module
module.exports = 'Hello Geek';
- Import File name Display.js
// Importing modulevar msg = import('./Message.js');console.log(msg);
Output:
Hello GeekFeatures:
- Asynchronous loading of modules.
- Supports named exports and default exports.
- Enables tree shaking, where unused exports are omitted in the final bundle.
Difference between node.js require and ES6 import and export:
| Nodejs require | ES6 import and export |
|---|---|
| Require is Non-lexical, it stays where they have put the file. | Import is lexical, it gets sorted to the top of the file. |
| It can be called at any time and place in the program. | It can’t be called conditionally, it always run in the beginning of the file. |
| You can directly run the code with require statement. | To run a program containing import statement you have to use experimental module feature flag. |
| If you want to use require module then you have to save file with ‘.js’ extension. | If you want to use import module then you have to save file with ‘.mjs’ extension. |
It is a method in CommonJS module. | It is a part of ES6 Module. |
It loads the modules synchronously. | It loads the modules asynchronously. |
NOTE: In Node.js, using both `require` and `import` concurrently is prohibited; it’s recommended to use `require` over `import` to avoid the experimental module flag requirement.
Conclusion
Both require and import/export are used to load modules in Node.js, but they differ in their module systems, loading mechanisms, and syntax. While require is synchronous and based on CommonJS, ES6 import/export offers asynchronous, statically-analyzable imports, making it more suitable for modern JavaScript development.
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