// Write your code below
const is2p2 = checkThatTwoPlusTwoEqualsFourAMillionTimes;
is2p2();
console.log(is2p2.name); // rename the function

• Abstraction allows us to write complicated code in a way that’s easy to reuse, debug, and understand for human readers
• We can work with functions the same way we would any other type of data including reassigning them to new variables
• JavaScript functions are first-class objects, so they have properties and methods like any object
• Functions can be passed into other functions as parameters
• A higher-order function is a function that either accepts functions as parameters, returns a function or both

const fruits = ['mango', 'papaya', 'pineapple', 'apple'];

// Iterate over fruits below
fruits.forEach(function(element){
  console.log(`I want to eat a ${element}`);
})

// map function
const animals = ['Hen', 'elephant', 'llama', 'leopard', 'ostrich', 'Whale', 'octopus', 'rabbit', 'lion', 'dog'];

// Create the secretMessage array below
const secretMessage = animals.map(animal => animal[0]);
console.log(secretMessage)
console.log(secretMessage.join(''));

const bigNumbers = [100, 200, 300, 400, 500];

// Create the smallNumbers array below
const smallNumbers = bigNumbers.map(num => num/100);

console.log(smallNumbers)

// filter function
const randomNumbers = [375, 200, 3.14, 7, 13, 852];

// Call .filter() on randomNumbers below
const smallNumbers = randomNumbers.filter(num => {
  return num < 250;
})

const favoriteWords = ['nostalgia', 'hyperbole', 'fervent', 'esoteric', 'serene'];

// Call .filter() on favoriteWords below

const longFavoriteWords = favoriteWords.filter(word => {
  return word.length > 7;
})

// findIndex function
const jumbledNums = [123, 25, 78, 5, 9]; 
 
const lessThanTen = jumbledNums.findIndex(num => {
  return num < 10;
});

// reduce function
const newNumbers = [1, 3, 5, 7];

const newSum = newNumbers.reduce((accumulator, currentValue) => {
  console.log('The value of accumulator: ', accumulator);
  console.log('The value of currentValue: ', currentValue);
  return accumulator + currentValue;
})

console.log(newSum);

const words = ['unique', 'uncanny', 'pique', 'oxymoron', 'guise'];

// Something is missing in the method call below

console.log(words.some(word => {
  return word.length < 6;
}));

// Use filter to create a new array
const interestingWords = words.filter((word) => {return word.length > 5});

// Make sure to uncomment the code below and fix the incorrect code before running it

console.log(interestingWords.every((word) => {return word.length > 5}));

const cities = ['Orlando', 'Dubai', 'Edinburgh', 'Chennai', 'Accra', 'Denver', 'Eskisehir', 'Medellin', 'Yokohama'];

const nums = [1, 50, 75, 200, 350, 525, 1000];

//  Choose a method that will return undefined
cities.forEach(city => console.log('Have you visited ' + city + '?'));

// Choose a method that will return a new array
const longCities = cities.filter(city => city.length > 7);

// Choose a method that will return a single value
const word = cities.reduce((acc, currVal) => {
  return acc + currVal[0]
}, "C");

console.log(word)

// Choose a method that will return a new array
const smallerNums = nums.map(num => num - 5);

// Choose a method that will return a boolean value
nums.every(num => num < 0);
// OR nums.some(num => num < 0);

• .forEach() is used to execute the same code on every element in an array but does not change the array and returns undefined.
• .map() executes the same code on every element in an array and returns a new array with the updated elements.
• .filter() checks every element in an array to see if it meets certain criteria and returns a new array with the elements that return truthy for the criteria.
• .findIndex() returns the index of the first element of an array which satisfies a condition in the callback function. It returns 1 if none of the elements in the array satisfies the condition.
• .reduce() iterates through an array and takes the values of the elements and returns a single value.