Lecture 3: Additional Materials for ES6
 ES6 on Windows + More ES6 + More Exercises Kobkrit Viriyayudhakorn, Ph.D. CEO of iApp Technology Limited. kobkrit@gmail.com http://www.kobkrit.com
All source code • https://github.com/kobkrit/learn-react-native
How to try ES6 and Beyond with on Windows (1) Open Command Line with “Run as Administrator”
(2) Create Directory at C:es6 and then run “npm init”
(3) Press Enter Many Times Until All Questions are Answered
(4) npm install --save-dev babel-cli 
 babel-preset-stage-0
(4) notepad link.cmd
(5) Type “doskey babel-node=.node_modules.binbabel- node $*” and hit file > save
(6) Go back to command line, type “link.cmd”
(7) echo {"presets":["stage-0"]} > .babelrc
(8) notepad 1.js
(9) Type down some ES6 code, e.g., 
 console.log(‘Hello World!’); + Hit Save
(10) babel-node 1.js
Alias is not persistence! • If you closed the command line windows, enter c: es6 again, and always run link.cmd • Open command line program • cd c:es6 • link.cmd • babel-node somefile.js
More on .
Math
Set
Exercise (1) Write down a function that sum every element in array. E.g. sumArray([12,3,4,1,2,3]) = 25 sumArray([12,3,4,1,2,3]); //=> 25
 
 sumArray([1,2,3]); //=> 6
function sumArray(arr){ }
Exercise (2) Write function that count word size case-insensitively. wordHistogram('Hello world hello earth') //=> {hello : 2, world : 1, earth : 1 } wordHistogram('dog eat cat cat eat dog') //=> {dog : 2, eat : 2, cat : 2 } wordHistogram('Na na na na na na na na na na na na na na na na na na na na na na na na Batman!’) //=> {Batman! : 1, na: 24} (https://www.youtube.com/watch?v=EtoMN_xi-AM)
function wordHistogram(str){ }
Exercises (3) Write the function that can unions two arrays and sort it ascendingly. unionsAndSort([5,3,2],[1,4,5]) // => [1,2,3,4,5,5] unionsAndSort([1,2,3],[4]) // => [1,2,3,4]
function unionsAndSort(a,b){ }
Exercises (4) Write the function that select only words that start with letter ‘a’ or ‘A’ in a string. onlyStartWithA(‘angulus is an angle in latin’); //=> ‘angulus an angle’ onlyStartWithA(‘apple is not an animal’); //=> ‘apple an animal’
function onlyStartWithA(str){ }
Exercises (5) Reverse Digits of an Integer reverseDigit(123); //=> 321
 reverseDigit(-456); //=> 654
function reverseDigit(num){ }

[React Native Tutorial] Lecture 3: More on ES6/ES2015