es6.js

/* eslint-disable */

// Refactor the following code to use the specified ES6 features.
// There are no automated tests.
// To make sure the code still works you can run this file using `node es6.js` from inside `/src`.

//----------------
// const, =>, default parameters, arrow functions default return statements using ()

let food = `pineapple`;

const isMyFavoriteFood = (food) => {
  food = food || `thousand-year-old egg`; //This sets a default value if `food` is falsey
  return food === `thousand-year-old egg`;
};

let isThisMyFavorite = isMyFavoriteFood(food);

//----------------
//const, class, template literals, enhanced object literals (foo: foo, -> foo,)

const User = (options) => {
  this.username = options.username;
  this.password = options.password;
  this.sayHi = () => {
    return `${this.username} says hello!`;
  };
}

let username = `JavaScriptForever`;
let password = `password`;

let me = new User({ username, password });

// ----------------
// let, const, =>, ... (spread operator)

const addArgs = () => {
  let sum = 0;
  for (let i = 0; i < arguments.length; i++) {
    sum += arguments[i];
  }
  return sum;
};

const argsToCb = (cb) => {
  const args = Array.prototype.slice.call(arguments);
  return cb(...args.splice(1));
};

let result = argsToCb(addArgs, 1, 2, 3, 4, 5); //result should be 15

/* eslint-enable */