3-array.js

var words = [
  'crab',
  'poison',
  'contagious',
  'simple',
  'bring',
  'sharp',
  'playground',
  'poison',
  'communion',
  'simple',
  'bring'
];

// Write a function uniqueArray that receives an array of words as a parameter. And remove the duplicates, and return a new array. 
// (indexOf)

function uniqueArray(words) {
  var wordsFilter = words.filter((element, index) => words.indexOf(element) == index);
  return wordsFilter;
} 



var words2 = [
  'machine',
  'subset',
  'trouble',
  'starting',
  'matter',
  'eating',
  'truth',
  'disobedience'
];

// Write a function doesWordExist that will take in an array of words as one argument, and a word to search for as the other. Return true if it exists, otherwise, return false. Don't use indexOf for this one.

function doesWordExist(words2, searchItem) {
  return words2.includes(searchItem);
}

doesWordExist(words2, 'machine'); // true;



var words3 = [
  'machine',
  'matter',
  'subset',
  'trouble',
  'starting',
  'matter',
  'eating',
  'matter',
  'truth',
  'disobedience',
  'matter'
];


// Write a function howManyTimes that will take in an array of words as one argument, and a word to search for as the other. The function will return the number of times that word appears in the array.

function howManyTimes(words3, searchItem) {
  var arr = [searchItem];
  words3.forEach(element => {
    if(arr.includes(element)) {
      arr.push(element);
    }
  });
  return arr.length - 1;
}

howManyTimes(words3, 'matter'); // 4
howManyTimes(words3, 'machine'); // 1
howManyTimes(words3, 'matter-machine'); // 0



// Using the reduce() method, how would you sum up the population of every country except China?
let data = [
  {
    country: 'China',
    pop: 1409517397,
  },
  {
    country: 'India',
    pop: 1339180127,
  },
  {
    country: 'USA',
    pop: 324459463,
  },
  {
    country: 'Indonesia',
    pop: 263991379,
  }
]

data.reduce((acc, value) => {
	if (value.country == 'China') {
		return acc;
	} else {
    return acc + value.pop;
  }
}, 0);


// Use reduce method and summorize the collection like
// { banana: 2, cherry: 3, orange: 3, apple: 2, fig: 1 }
const fruitBasket = [
  'banana',
  'cherry',
  'orange',
  'apple',
  'cherry',
  'orange',
  'apple',
  'banana',
  'cherry',
  'orange',
  'fig'
];

// var finalObject = {};

// fruitBasket.reduce((acc, value) => {
//   if (finalObject[acc] == 0) {
//     finalObject[acc]++;
//   }
//   if (!finalObject[value]) {
//     finalObject[value] = 0;
//   }

//   finalObject[value]++;
// }, 0);

// finalObject;

fruitBasket.reduce((acc, value) => {
  if (acc[value]) {
    acc[value]++;
  } else {
    acc[value] = 1;
  }
  return acc;
}, {});



// Bonus Question (Solve only if you have time)
var matrix = [
  [08,02,22,97,38,15,00,40,00,75,04,05,07,78,52,12,50,77,91,08],
  [49,49,99,40,17,81,18,57,60,87,17,40,98,43,69,48,04,56,62,00],
  [81,49,31,73,55,79,14,29,93,71,40,67,53,88,30,03,49,13,36,65],
  [52,70,95,23,04,60,11,42,69,24,68,56,01,32,56,71,37,02,36,91],
  [22,31,16,71,51,67,63,89,41,92,36,54,22,40,40,28,66,33,13,80],
  [24,47,32,60,99,03,45,02,44,75,33,53,78,36,84,20,35,17,12,50],
  [32,98,81,28,64,23,67,10,26,38,40,67,59,54,70,66,18,38,64,70],
  [67,26,20,68,02,62,12,20,95,63,94,39,63,08,40,91,66,49,94,21],
  [24,55,58,05,66,73,99,26,97,17,78,78,96,83,14,88,34,89,63,72],
  [21,36,23,09,75,00,76,44,20,45,35,14,00,61,33,97,34,31,33,95],
  [78,17,53,28,22,75,31,67,15,94,03,80,04,62,16,14,09,53,56,92],
  [16,39,05,42,96,35,31,47,55,58,88,24,00,17,54,24,36,29,85,57],
  [86,56,00,48,35,71,89,07,05,44,44,37,44,60,21,58,51,54,17,58],
  [19,80,81,68,05,94,47,69,28,73,92,13,86,52,17,77,04,89,55,40],
  [04,52,08,83,97,35,99,16,07,97,57,32,16,26,26,79,33,27,98,66],
  [88,36,68,87,57,62,20,72,03,46,33,67,46,55,12,32,63,93,53,69],
  [04,42,16,73,38,25,39,11,24,94,72,18,08,46,29,32,40,62,76,36],
  [20,69,36,41,72,30,23,88,34,62,99,69,82,67,59,85,74,04,36,16],
  [20,73,35,29,78,31,90,01,74,31,49,71,48,86,81,16,23,57,05,54],
  [01,70,54,71,83,51,54,69,16,92,33,48,61,43,52,01,89,19,67,48],
];
// In the 20×20 grid above What is the greatest product of four adjacent numbers in the same direction (up, down, left, right)?
// Write a function greatestProduct to find the answer!