Shulou(Shulou.com)06/03 Report--

This article mainly explains "what is the function of promisify () method in Node.js". Interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn "what is the function of the promisify () method in Node.js?"

Node.js 's built-in util module has a promisify () method.

1. This method converts callback-based functions into Promise-based functions.

2. You can use Promise chain and async/await in combination with callback-based API.

Node.js 's fs module needs to use callbacks when reading files:

Const fs = require ('fs') fs.readFile ('. / package.json', function callback (err) Buf) {const obj = JSON.parse (buf.toString ('utf8')) console.log (obj.name) / /' Example'-> package.json package name}) you can use util.promisify () to convert the callback function of fs.readFile () into a return Promise function: const fs = require ('fs') const util = require (' util') / / convert fs.readFile () into a function that takes the same argument but returns Promise. Const readFile = util.promisify (fs.readFile) / / you can now use readFile () with await! Const buf = await readFile ('. / package.json') const obj = JSON.parse (buf.toString ('utf8')) console.log (obj.name) / /' Example' here, I believe you have a deeper understanding of "what is the role of promisify () method in Node.js". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.