lesson_8_ex2.js

// The following arrays will be used through the questions:
const words = [ 'cattywampus', 'snickersnee', 'lollygag', 'pandiculation', 'ratoon' ];
const numbers = [ 8, 3, 22, 0, -73, 15 ];

// Question 1: 
// Use forEach to console.log all the words in the words array. Do not write a for loop. 
function logWords(){
  // words.forEach(word => console.log(word));
  words.forEach(function(word){
    console.log(word)
  })
}

// Question 2: Use forEach to console.log the each number in the numbers array divided by two
// It should console.log: 
// 4
// 1.5
// ...etc. 
function logHalfNumbers(){
  // numbers.forEach(number => console.log(number / 2))
  
  numbers.forEach(function(number) {
    console.log(number / 2)
  })
}

// Question 3: Using the getFirstLetter function below as your callback,
//             use map to create an array contaning the first letter of 
//             every word from the words array.

function getFirstLetter(word) {
  // return word.charAt(0)
  return word[0]
}

// const getFirstLetter = word => word[0]
// const getFirstLetter = word => word.charAt(0)

const firstLetters = words.map(getFirstLetter);

// Question 4: Use map to create an array containing the last letter of every word
//             from the words array. 

const lastLetters = words.map(function(word) {
  // return word.chartAt(word.length - 1)
  return word[word.length - 1]
});

// const lastLetters = words.map(word => word[word.length - 1])
// const lastLetters = words.map(word => word.charAt(word.length - 1))

// Question 5: Use map to create an array containing the reversed version of each word
//             from the word array. For example, the first entry will be 'supmawyttac'.

const reversedWords = words.map(function(word) {
  return word.split("").reverse.join("")
});

// const reversedWords = words.map(word => word.split("").reverse.join(""))

// Question 6: Use map to create an array containing the absolute value of every number
//             in the numbers array.

const absoluteNumbers = numbers.map(function(number) {
  if (number < 0) return -number
  return number
});

// const absoluteNumbers = numbers.map(function(number) {
//   if (number < 0) return number * - 1
//   return number
// });

// const absoluteNumbers = numbers.map(function(number) {
//   return Math.abs(number)
// });

// const absoluteNumbers = numbers.map(number => number < 0 ? -number : number);

// Question 7: Use map to create an array containing each number from the numbers array
//             rounded to the nearest 10. For example: 10, 0, 20, 0, etc. 

const roundedToTenNumbers = numbers.map(function(number) {
  return Math.round(number) * 10
});

// const roundedToTenNumbers = numbers.map(n => Math.round(n) * 10);

// Question 8: Use map to create an array that contains only the words from the words
//             array containing 's'. All other words should be replaced with null.
//             For example: 'cattywampus', 'snickersnee', null, etc. 

const wordsWithS = words.map(function(word) {
  if (word.includes('s')) return word
  return null
});

const wordsWithS = words.map(word => word.includes('s') ? word : null);

// Stretch Questions:
// The stretch question will use the array method reduce, which was only briefly reviewed 
// in the lecture. Refer to online documentation for more information on reduce. 

// Question 9: Use reduce to sum up all of the numbers in the numbers array. 

function sum(currentTotal, nextNumber) {
  return currentTotal + nextNumber
}

// const sum = (currentTotal, nextNumber) => currentTotal + nextNumber

const sumTotal = numbers.reduce(sum);

// Question 10: Use reduce to find the word from the words array that is last in the alphabet.

const alphabeticallyLast = words.reduce(function(last, current) {
  if (last > current) return last
  return current
});

// const alphabeticallyLast = words.reduce((last, current) => last < current ? last : current)

You ought to do them all in gist and set them up with V.1 ans and V.2 ans if you feel froggy