ArrayMethods.md

Array Methods

const collection = [1, 2, 3, 4, 5, 6, 7, 8];

const flowers = [
  {
    name: "Rose",
    price: 30,
  },
  {
    name: "Orchid",
    price: 150,
  },
  {
    name: "Lily",
    price: 100,
  },
  {
    name: "Tulip",
    price: 80,
  },
];

// includes - includes checks if the array includes the item passed.
console.log(collection.includes(4)); //true
console.log(collection.includes(9)); //false

// some - checks if there is atleast one of the item in array that passes the given condition.
const largeNum = collection.some((num) => num > 4);
console.log("Large Number", largeNum); //true

const negativeNum = collection.some((num) => num < 0);
console.log("Negative Number", negativeNum); // false

// every - checks if all the items in the array pass the given condition.
const lessThanNine = collection.every((num) => num < 9);
console.log("Less than 9", lessThanNine); // true

const lessThanFive = collection.every((num) => num < 5);
console.log("Less than 5", lessThanFive); // false - not all are less than 5

//filter - returns a new array that pass the particular given condition
const filtered = collection.filter((num) => num > 3);
console.log("Filtered", filtered); // [4,5,6,7,8]

//map - return new array with results of the called function.
const addThree = collection.map((num) => num + 3);
console.log("Array with 3 added", addThree); // [ 4, 5, 6, 7, 8, 9, 10, 11 ]

//reduce - Applies a function against an accumulator and each element in the array (from left to right) to reduce it to a single value.
const flowerPricesTotal = flowers.reduce((sum, flower) => {
  //   console.log(sum, flower);
  return sum + flower.price;
}, 0); //optionally supplied initial value. If not given, the 0th element of the array is considered.
console.log("Flower Prices", flowerPricesTotal); //360

// Question - Write a script to find the sum of ages of all dogs in years.

// const animals = [
//   {
//     age: 24,
//     type: "dog",
//   },
//   {
//     age: 60,
//     type: "dog",
//   },
//   {
//     age: 36,
//     type: "cat",
//   },
// ];

// Age is in months, has to be converted in months.

// const dogs = animals.filter((animal) => animal.type === "dog");
// console.log("Dogs", dogs);
// const dogsAgeTotal = dogs.reduce((age, dog) => {
//   return age + dog.age;
// }, 0);
// console.log("Dogs Total Age", dogsAgeTotal / 12);

// const dogsTotalAge = animals
//   .filter((animal) => animal.type === "dog")
//   .map((animal) => animal.age / 12)
//   .reduce((age, dog) => {
//     return age + dog;
//   }, 0);
// console.log("Dogs Total Age", dogsTotalAge);

let result = animals.reduce((totalAge, item) => {
  return item.type === "dog" ? totalAge + item.age : totalAge;
}, 0);

console.log(result / 12);