funador

const nums = [2, 6, 3, 10]
const nums2 = [2, 4, 1, 2]

const duplicates2 = arr => {
  
  for (let i = 0; i < arr.length; i++) {
    
    // Cut down on our work by not considering pairs
    // we have already looked at
    for (let j = i + 1; j < arr.length; j++) {

funador

const nums = [2, 6, 3, 10]
const nums2 = [2, 4, 1, 2]

const duplicates = arr => {
  
  for (let i = 0; i < arr.length; i++) {
    for (let j = 0; j < arr.length; j++) {
      
      // If the indexes do not match but the 
      // values do, we have a duplicate!

funador

const vetApprovedDogs = [
  {name: 'Snookums', needsShots: false, breed: 'pug', age: 2},
  {name: 'Thor', needsShots: false, breed: 'hound', age: 1},
  {name: 'Wunderbar', needsShots: false, breed: 'pug', age: 9},
]

// The big report for the city, have to be sure we get this right!
const reportForCity = vetApprovedDogs.myReduce((report, dog) => {
  
  // Is this breed not in the report?

funador

const vetApprovedDogs = [
  {name: 'Snookums', needsShots: false, breed: 'pug', age: 2},
  {name: 'Thor', needsShots: false, breed: 'hound', age: 1},
  {name: 'Wunderbar', needsShots: false, breed: 'pug', age: 9},
]

// I need a little more practice with map! 
const allDogsAges = vetApprovedDogs.map(dog => dog.age)

console.log(allDogsAges) // [2, 1, 9]

funador

const dogs = [
  {name: 'Snookums', needsShots: true, breed: 'pug', age: 2},
  {name: 'Thor', needsShots: true, breed: 'hound', age: 1},
  {name: 'Wunderbar', needsShots: false, breed: 'pug', age: 9},
]

// We are going to create a new array of our vet approved dogs!
const vetApprovedDogs = dogs.myMap((dog) => {

  // The vet makes his approval

funador

Array.prototype.myFilter = function(callback) {
  const arr = []

  for (let i = 0; i < this.length; i++) {
    const item = this[i]

    if(callback(item, i, this)) {
      arr.push(item)
    }
  }

funador

// filter
Array.prototype.myFilter = function(func) {
  const arr = []

  for (let i = 0; i < this.length; i++) {
    const item = this[i]

    if(func(item, i, this)) {
      arr.push(item)
    }

funador

Array.prototype.myReduce = function(func, initialValue) {
  const arr = arguments.length > 1
    ? [initialValue, ...this]
    : this

  let accumulator = arr[0]

  for (let i = 1; i < arr.length; i++) {
    accumulator = func(accumulator, arr[i], i, this) 
  }

funador

Array.prototype.myMap = function(callback) {
  const arr = []

  for (let i = 0; i < this.length; i++) {
    arr.push(callback(this[i], i , this))   
  }

  return arr
}

funador

const dogs = [
  {name: 'Snookums', needsShots: true, breed: 'pug', age: 2},
  {name: 'Thor', needsShots: true, breed: 'hound', age: 1},
  {name: 'Wunderbar', needsShots: false, breed: 'pug', age: 9},
]

// Lets see how a filter method might work... 

const dogsToSeeVet = dogs.myFilter(function(dog) {