promise in javascript

promise,tipjs

const fs = require('fs')

const readFileWithPromise = file => {
  return new Promise((resolve, reject) => {
    fs.readFile(file, (err, data) => {
      if (err) {
        reject(err)
      } else {
        resolve(data)
      }
    })
  })
}

readFileWithPromise('/etc/passwd')
  .then(data => {
    console.log(data.toString())
    return readFileWithPromise('/etc/profile')
  })
  .then(data => {
    console.log(data.toString())
  })
  .catch(err => {
    console.log(err)
  })

Callback in javascript

Convert Array-like to True Array

await axios get

10 mẹo sử dụng array và object trong javascript

Object.keys và Object.getOwnPropertyNames