SastraNababan

import firebase from 'react-native-firebase'
const config = {
  apiKey: "AIzaSyBiXJTuUD5Ya9PUM81l5qQ83bOZIAlvIGE",
  authDomain: "react-native-73f21.firebaseapp.com",
  databaseURL: "https://react-native-73f21.firebaseio.com",
  projectId: "react-native-73f21",
  storageBucket: "react-native-73f21.appspot.com",
  messagingSenderId: "150783570753"
};
 

SastraNababan

[
  {
    "id": 64833,
    "productName": "Sleek Steel Mouse",
    "price": 4520000,
    "productDescription": "Dolores distinctio labore necessitatibus iste voluptatem repudiandae repellendus. Sit voluptas dicta nisi et consequuntur. Dolores a quia atque molestias. Eligendi excepturi consectetur maiores ea dolores minima repellendus dolores omnis. Nulla nam eius odio repellendus itaque magni.\n \rPariatur accusantium maxime aut et vel earum repellendus perspiciatis incidunt. Sed debitis est et odio adipisci eum est beatae quam. Voluptatem sint esse. Fuga sapiente nam. Ut veritatis incidunt rerum amet dolores culpa. Exercitationem maiores autem accusantium sint consequatur et et.\n \rQui eos aut iure aut reprehenderit at excepturi dolor distinctio. Omnis rem nulla. Vitae ut molestias aut nihil vel ut ipsam. Qui omnis sit qui fugit quia praesentium quia ad facilis.",
    "image": "http://lorempixel.com/340/280/food/1"
  },
  {
    "id": 98125,

SastraNababan

import React from 'react'
import { StyleSheet, Text, View,Dimensions } from 'react-native'
const dim = Dimensions.get('screen')

export default class App extends React.Component {
  state = {
    screenWidth:dim.width,
    screenHeight:dim.height,
    orientation:this._getOrientation(dim.width,dim.height)
  }

SastraNababan

new Promise((resolve, reject) => {
  reject('reject')
  console.log('ALWAYS REACHED')
}).then(() => console.log("RESOLVED"))
.catch(() => console.log("REJECTED"));

new Promise((resolve, reject) => {
  throw('err')
  console.log('NEVER REACH')
})

SastraNababan

// 1. Anonymous Async Function
let main = (async function() {
  let value = await doAsync();
})();


// 2. Async Function Declaration
let main = async function() {
  let value = await doAsync();

SastraNababan

const firstPromise= () => (new Promise((resolve,reject) => {
  setTimeout(() =>{ resolve('first Promise')},1000) 
}))

const secondPromise = () => ( new Promise((resolve,reject) =>{
  setTimeout(() =>{ resolve('second Promise')},1000) 
}))

const thirdPromise = () => ( new Promise((resolve,reject) =>{

SastraNababan

async function fetchWithAsyncAwait (id)  {
  try {
    let response = await fetch(endpoint + id)
    response = await response.json()
    console.log(response)
  } catch (error) {
    console.log('opps' + error)
  }
}

SastraNababan

/* Promise */
const endpoint ='https://jsonplaceholder.typicode.com/users/'
function fetchWithPromise (id)  {
  fetch(endpoint + id)
  .then(response => {
    return response.json();
  })
  .then(user => {
    console.log(user);
  })

SastraNababan

const doFetch = (url) => fetch(url).then(result => result.json())
let urls =[
  'https://jsonplaceholder.typicode.com/posts/1',
  'https://jsonplaceholder.typicode.com/posts/2',
  'https://jsonplaceholder.typicode.com/posts/3',
  'https://jsonplaceholder.typicode.com/posts/4',
]

let promises=[]

SastraNababan

Promise.seriousRace = function(promises) {
  let indexPromises = promises.map((p, index) => p.catch(() => {throw index}))
  return Promise.race(indexPromises).catch(index => {
    let p = promises.splice(index, 1)[0]
    p.catch(e => console.log( e +  ' terjatuh,ahh sudahlah lanjutkan saja'))
    return Promise.seriousRace(promises)
  })
}

let peserta1 = new Promise(resolve => setTimeout(resolve, 30, 'Peserta 1'))