destructuring.js

////////////////////Object Destructuring 1////////////////////
//What does the following code return/print?
let facts = {numberPlanets: 8, yearNeptuneDiscovered: 1846};
let {numberPlanets, yearNeptuneDiscovered} = facts;

//console.log(numberPlanets); // 8
//console.log(yearNeptuneDiscovered); // 1846

////////////////////Object Destructuring 2////////////////////
//What does the following code return/print?
let planetFacts = {
  numPlanets: 8,
  yearNeptuneDiscovered: 1846,
  yearMarsDiscovered: 1659
};

let {numPlanets, ...discoveryYears} = planetFacts;

//console.log(discoveryYears); // {yearNeptuneDiscovered: 1846, yearMarsDiscovered: 1659};

////////////////////Object Destructuring 3//////////////////
//What does the following code return/print?
function getUserData({firstName, favoriteColor="green"}){
  return `Your name is ${firstName} and you like ${favoriteColor}`;
}

getUserData({firstName: "Alejandro", favoriteColor: "purple"}) // 'Your name is Alejandro and you like purple';
getUserData({firstName: "Melissa"}) // 'Your name is Melissa and you like green';
getUserData({}) // 'Your name is undefined and you like green';


/////////////////////Array Destructuring 1//////////////////
//What does the following code return/print?
let [first, second, third] = ["Maya", "Marisa", "Chi"];

//console.log(first); // Maya
//console.log(second); // Marisa
//console.log(third); // Chi


////////////////////Array Destructuring 2//////////////////
//What does the following code return/print?
let [raindrops, whiskers, ...aFewOfMyFavoriteThings] = [
  "Raindrops on roses",
  "whiskers on kittens",
  "Bright copper kettles",
  "warm woolen mittens",
  "Brown paper packages tied up with strings"
]

//console.log(raindrops); // Raindrops on roses
//console.log(whiskers); // whiskers on kittens
//console.log(aFewOfMyFavoriteThings); // ["Bright copper kettles", "warm woolen mittens", "Brown paper packages tied up with strings"]


/////////////////////Array Destructuring 3///////////////
//What does the following code return/print?
let numbers = [10, 20, 30];
[numbers[1], numbers[2]] = [numbers[2], numbers[1]]

//console.log(numbers) // [10, 30, 20]


//////////////////////////////## **ES2015 Refactoring**//////////////////////////////////////////////

//In this exercise, you’ll refactor some ES5 code into ES2015.

///////////ES5 Assigning Variables to Object Properties//////////////////
// var obj = {
//   numbers: {
//     a: 1,
//     b: 2
//   }
// };
// var a = obj.numbers.a;
// var b = obj.numbers.b;

// ES2015 Object Destructuring:
const obj = {
    numbers: {
        a: 1,
        b: 2
    }
};
const {numbers: {a, b}} = obj;


///////////////////////////ES5 Array Swap//////////////////////////////////
// var arr = [1, 2];
// var temp = arr[0];
// arr[0] = arr[1];
// arr[1] = temp;

///////////////ES2015 One-Line Array Swap with Destructuring///////////////
let arr = [1, 2];
[arr[0], arr[1]] = [arr[1], arr[0]];


///////////////////////////////////////////////////////////////## **raceResults()**////////////////////////////////////////////

// Write a function called ***raceResults*** which accepts a single array argument. 
//It should return an object with the keys ***first***, ***second***, ***third***, and ***rest***.

// **Write a *one line* function to make this work using: 
// (1) An arrow function, (2) Destructuring, (3 `Enhanced`) object assignment (same key/value shortcut).

const raceResults = ([first, second, third, ...rest]) => {return {first, second, third, rest}};