What is the difference between require(x) and ES6 import x in Node.js?
Câu trả lời
In Node.js, require(x) and ES6 import x are two different mechanisms for including modules into a file. Here are the key differences between them:
Syntax and Loading Mechanism
require(x) uses the CommonJS syntax and is a built-in function in Node.js that is used to load modules. It takes the module's path as an argument and returns the exported content of the module. require() is synchronous, meaning it loads modules one after another, blocking the execution until the module is loaded[1].
import x uses the ES6 (ECMAScript 2015) module syntax for importing modules. It is more modern and standardized compared to require(). import is asynchronous and supports lazy loading, meaning it loads modules only when they are needed, which can improve performance[1].
Scope and Hoisting
require is non-lexical, meaning it stays where you put it in the code. It can be called at any time and place in the program[2].
import is lexical and gets hoisted to the top of the file. It cannot be called conditionally and always runs at the beginning of the file[2].
Module Support
require() can be used to load both CommonJS modules and ES modules (with some limitations)[1].
import is designed to work with ES modules and requires the use of the .mjs file extension when working with Node.js[1][2].
Export Support
require() does not have explicit support for default exports. Named exports are supported via destructuring[1].
import supports both default exports and named exports directly. For example, you can use import { name } from 'module' to import named exports[1].
Static Analysis and Tree Shaking
require() does not support static analysis, which means tools cannot determine which parts of a module are used or unused before runtime[1].
import supports static analysis, enabling tree shaking—a process where unused code is removed during the build ...
