Answers for "map function in js"

javascript map function

const posts = [
  { id: 1, title: "Sample Title 1", description: "Lorem ipsum dolor sit amet, consectetur adipiscing elit..." },
  { id: 2, title: "Sample Title 2", description: "Lorem ipsum dolor sit amet, consectetur adipiscing elit..." },
  { id: 3, title: "Sample Title 3", description: "Lorem ipsum dolor sit amet, consectetur adipiscing elit..." },
];
// ES2016+
// Create new array of post IDs. I.e. [1,2,3]
const postIds = posts.map((post) => post.id);
// Create new array of post objects. I.e. [{ id: 1, title: "Sample Title 1" }]
const postSummaries = posts.map((post) => ({ id: post.id, title: post.title }));

// ES2015
// Create new array of post IDs. I.e. [1,2,3]
var postIds = posts.map(function (post) { return post.id; });
// Create new array of post objects. I.e. [{ id: 1, title: "Sample Title 1" }]
var postSummaries = posts.map(function (post) { return { id: post.id, title: post.title }; });

How does map works in javascript?

const products = [
    { name: 'Laptop', price: 32000, brand: 'Lenovo', color: 'Silver' },
    { name: 'Phone', price: 700, brand: 'Iphone', color: 'Golden' },
    { name: 'Watch', price: 3000, brand: 'Casio', color: 'Yellow' },
    { name: 'Aunglass', price: 300, brand: 'Ribon', color: 'Blue' },
    { name: 'Camera', price: 9000, brand: 'Lenovo', color: 'Gray' },
];

const productName = products.map(product => product.name);
console.log(productName);
//Expected output:[ 'Laptop', 'Phone', 'Watch', 'Aunglass', 'Camera' ]

array map javascript

const array1 = [1, 4, 9, 16];

// pass a function to map
const map1 = array1.map(x => x * 2);

console.log(map1);
// expected output: Array [2, 8, 18, 32]

javascript map

array.map((item) => {
  return item * 2
} // an example that will map through a a list of items and return a new array with the item multiplied by 2

how the map function works javascript

const array = [2, 5, 9];
let squares = array.map((num) => num * num);

console.log(array); // [2, 5, 9]
console.log(squares); // [4, 25, 81]

map function in js

let kvArray = [{key: 1, value: 10},
               {key: 2, value: 20},
               {key: 3, value: 30}]

let reformattedArray = kvArray.map(obj => {
   let rObj = {}
   rObj[obj.key] = obj.value
   return rObj
})
// reformattedArray is now [{1: 10}, {2: 20}, {3: 30}],

// kvArray is still:
// [{key: 1, value: 10},
//  {key: 2, value: 20},
//  {key: 3, value: 30}]

javascript map function

const posts = [
  { id: 1, title: "Sample Title 1", description: "Lorem ipsum dolor sit amet, consectetur adipiscing elit..." },
  { id: 2, title: "Sample Title 2", description: "Lorem ipsum dolor sit amet, consectetur adipiscing elit..." },
  { id: 3, title: "Sample Title 3", description: "Lorem ipsum dolor sit amet, consectetur adipiscing elit..." },
];
// ES2016+
// Create new array of post IDs. I.e. [1,2,3]
const postIds = posts.map((post) => post.id);
// Create new array of post objects. I.e. [{ id: 1, title: "Sample Title 1" }]
const postSummaries = posts.map((post) => ({ id: post.id, title: post.title }));

// ES2015
// Create new array of post IDs. I.e. [1,2,3]
var postIds = posts.map(function (post) { return post.id; });
// Create new array of post objects. I.e. [{ id: 1, title: "Sample Title 1" }]
var postSummaries = posts.map(function (post) { return { id: post.id, title: post.title }; });

How does map works in javascript?

const products = [
    { name: 'Laptop', price: 32000, brand: 'Lenovo', color: 'Silver' },
    { name: 'Phone', price: 700, brand: 'Iphone', color: 'Golden' },
    { name: 'Watch', price: 3000, brand: 'Casio', color: 'Yellow' },
    { name: 'Aunglass', price: 300, brand: 'Ribon', color: 'Blue' },
    { name: 'Camera', price: 9000, brand: 'Lenovo', color: 'Gray' },
];

const productName = products.map(product => product.name);
console.log(productName);
//Expected output:[ 'Laptop', 'Phone', 'Watch', 'Aunglass', 'Camera' ]

array map javascript

const array1 = [1, 4, 9, 16];

// pass a function to map
const map1 = array1.map(x => x * 2);

console.log(map1);
// expected output: Array [2, 8, 18, 32]

javascript map

array.map((item) => {
  return item * 2
} // an example that will map through a a list of items and return a new array with the item multiplied by 2

how the map function works javascript

const array = [2, 5, 9];
let squares = array.map((num) => num * num);

console.log(array); // [2, 5, 9]
console.log(squares); // [4, 25, 81]

map function in js

let kvArray = [{key: 1, value: 10},
               {key: 2, value: 20},
               {key: 3, value: 30}]

let reformattedArray = kvArray.map(obj => {
   let rObj = {}
   rObj[obj.key] = obj.value
   return rObj
})
// reformattedArray is now [{1: 10}, {2: 20}, {3: 30}],

// kvArray is still:
// [{key: 1, value: 10},
//  {key: 2, value: 20},
//  {key: 3, value: 30}]