console(控制台)


稳定性: 2 - 稳定

console 模块提供了一个简单的调试控制台,类似于 Web 浏览器提供的 JavaScript 控制台。

该模块导出两个特定组件:

  • Console 类,包含 console.log()console.error()console.warn() 等方法,可用于写入任何 Node.js 流。
  • 全局的 console 实例,配置为写入 process.stdoutprocess.stderr。 使用时无需调用 require('console')

注意:全局的 console 对象的方法既不像浏览器中的 API 那样总是同步的,也不像其他 Node.js 流那样总是异步的。 详见进程 I/O

使用全局 console 的示例:

console.log('你好世界');
// 打印到 stdout: 你好世界
console.log('你好%s', '世界');
// 打印到 stdout: 你好世界
console.error(new Error('错误信息'));
// 打印到 stderr: [Error: 错误信息]

const name = '描述';
console.warn(`警告${name}`);
// 打印到 stderr: 警告描述

使用 Console 类的示例:

const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);

myConsole.log('你好世界');
// 打印到 out: 你好世界
myConsole.log('你好%s', '世界');
// 打印到 out: 你好世界
myConsole.error(new Error('错误信息'));
// 打印到 err: [Error: 错误信息]

const name = '描述';
myConsole.warn(`警告${name}`);
// 打印到 err: 警告描述

Stability: 2 - Stable

The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.

The module exports two specific components:

  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without calling require('console').

Warning: The global console object's methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.

Example using the global console:

console.log('hello world');
// Prints: hello world, to stdout
console.log('hello %s', 'world');
// Prints: hello world, to stdout
console.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to stderr

const name = 'Will Robinson';
console.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to stderr

Example using the Console class:

const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);

myConsole.log('hello world');
// Prints: hello world, to out
myConsole.log('hello %s', 'world');
// Prints: hello world, to out
myConsole.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to err

const name = 'Will Robinson';
myConsole.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to err