SastraNababan

let peserta1 = new Promise(resolve => setTimeout(resolve, 30, 'Peserta 1'))
let peserta2 = new Promise((resolve,reject) => setTimeout(reject, 20, 'Peserta 2'))
let peserta3 = new Promise(resolve => setTimeout(resolve, 50, 'Peserta 3'))
let peserta4 = new Promise(resolve => setTimeout(resolve, 100, 'Peserta 4'))
let peserta5 = new Promise(resolve => setTimeout(resolve, 90, 'Peserta 5'))
 
Promise.race([peserta1, peserta2, peserta3, peserta4, peserta5])
    .then(val => console.log('Balapan selesai,Pemenangnya adalah:', val))
    .catch(err => console.log('Balapan dihentikan karena : ', err));

SastraNababan

let peserta1 = new Promise(resolve => setTimeout(resolve, 30, 'Peserta 1.'))
let peserta2 = new Promise(resolve => setTimeout(resolve, 20, 'Peserta 2.'))
let peserta3 = new Promise(resolve => setTimeout(resolve, 50, 'Peserta 3.'))
let peserta4 = new Promise(resolve => setTimeout(resolve, 100, 'Peserta 4.'))
let peserta5 = new Promise(resolve => setTimeout(resolve, 90, 'Peserta 5.'))
 
Promise.race([peserta1, peserta2, peserta3, peserta4, peserta5])
    .then(val => console.log('Balapan selesai,Pemenangnya adalah:', val))
    .catch(err => console.log('Balapan dihentikan karena : ', err));

SastraNababan

const getPost = () => fetch('https://jsonplaceholder.typicode.com/posts/1')
const getAuthor = (id) => fetch('https://jsonplaceholder.typicode.com/users/' + id)
const getComment = (id) => fetch('https://jsonplaceholder.typicode.com/users/' + id)

var a = getPost().then(res => res.json()) // #1 get post
var b = a.then(res => getAuthor(res.id)).then(res => res.json()) // #2 get author
var c = a.then(res => getComment(res.id)).then(res => res.json()) //#3 get comment
Promise.all([a,b,c]).then(results => {
  console.log(results[0])
  console.log(results[1])

SastraNababan

const getPost = () => fetch('https://jsonplaceholder.typicode.com/posts/1')
const getAuthor = (id) => fetch('https://jsonplaceholder.typicode.com/users/' + id)
const getComment = (id) => fetch('https://jsonplaceholder.typicode.com/users/' + id)

var a = getPost().then(res => res.json()) // #1 get post
var b = a.then(res => getAuthor(res.id)).then(res => res.json()) // #2 get author
var c = a.then(res => getComment(res.id)).then(res => res.json()) //#3 get comment
Promise.all([a,b,c]).then(results => {
  console.log(results[0])
  console.log(results[1])

SastraNababan

const getPost = () => fetch('https://jsonplaceholder.typicode.com/posts/1')
const getAuthor = (id) => fetch('https://jsonplaceholder.typicode.com/users/' + id)
const getComment = (id) => fetch('https://jsonplaceholder.typicode.com/users/' + id)

getPost() // #1.fetch post
.then(postResponse => postResponse.json()) // #2. get & return post json 
.then(postResponse => getAuthor(postResponse.id) // #3. fetch author
  .then(authorResponse => authorResponse.json()  // #4 get & return author json
    .then(authorResponse => getComment(postResponse.id) // #5 fetch comment

SastraNababan

readFileContent("a.md", function (a){
  readFileContent("b.md", function (b){
    readFileContent("b.md", function (b){
        writeFileContent("result.md", a + b + c, function(){
            console.log("we are done");
        })
      })   
  })
})

SastraNababan

var a = readFileContent("a.md");
var b = readFileContent("b.md");
var c = readFileContent("c.md");
writeFileContent("result.md", a + b + c);
console.log("we are done");

SastraNababan

function readFileCallback(err,data){
  if (err){
    console.log('Error Read File :' + err);
  }else{
    console.log(data.toString())
  }
}
var data = fs.readFile('hello.md',readFileCallback)

SastraNababan

const fs = require('fs');
var data = fs.readFileSync('hello.md')
console.log('Read File Done :' + data.toString());

SastraNababan

function p1() {
 console.log('p1 done')
}

function p2(callback) {
 setTimeout(
  function() {
   console.log('p2 done')
    callback()