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JAVASCRIPT

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' ]
Comment

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]
Comment

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
Comment

javascript map

const items = [1, 2, 3, 4, 5, 6, 7, 8, 9];

const anotherItems = items.map(item => item * 2);

console.log(anotherItems);
Comment

javascript map function

/* Answer to: "javascript map function" */

/*
  <Array>.map() - One of the most useful in-built methods in JavaScript (imo).

  The map() method creates a new array populated with the results of calling
  a provided function on every element in the calling array.
 
  For more information, click on the source link.

  Let me make some examples of it's uses:
*/

let array = [1, 4, 9, 16];
array.map(num => num * 2); // [2, 8, 18, 32];
array.map(pounds => `£${pounds}.00`); // ["£1.00", "£4.00", "£9.00", "£16.00"];
array.map(item => Math.sqrt(item)); // [1, 2, 3, 4];
Comment

how to use the map method in javascript

const numbers = [1, 2, 3, 4, 5]; 

const bigNumbers = numbers.map(number => {
  return number * 10;
});
Comment

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]
Comment

map javascript

var numbers = [1, 4, 9];
var doubles = numbers.map(function(num) {
  return num * 2;
});
// doubles is now [2, 8, 18]. numbers still [1, 4, 9]
Comment

map in javascript

// Use map to create a new array in memory. Don't use if you're not returning
const arr = [1,2,3,4]

// Get squares of each element
const sqrs = arr.map((num) => num ** 2)
console.log(sqrs)
// [ 1, 4, 9, 16 ]

//Original array untouched
console.log(arr)
// [ 1, 2, 3, 4 ]
Comment

map method js

// Map objects are collections of key-value pairs. 
// A key in the Map may only occur once, it is unique in the Map 's collection
let map = new Map()
let keyArray = 'Array'
map.set(keyArray, [1, 2, 3, 4, 5])
map.get(keyArray) // 1, 2, 3, 4, 5
Comment

JS map

const newArray= array.map((data)=> data);
Comment

javascript map

const numbers = [0,1,2,3];

console.log(numbers.map((number) => {
  return number;
}));
Comment

javascript map

// make new array from edited items of another array
var newArray = unchangedArray.map(function(item, index){
  return item;	// do something to returned item
});

// same in ES6 style (IE not supported)
var newArray2 = unchangedArray.map((item, index) => item);
Comment

map in js

//map() methods returns a new array
const data = {name: "laptop", brands: ["dell", "acer", "asus"]}
let inside_data = data.brands.map((i) => {
	console.log(i); //dell acer asus
});
Comment

map in javascript

//map is higher order function 
const names= ["Shirshak","SabTech","Fiverr"]
const newNames= names.map(function(name){
 console.log(video)
})
console.log(newVideos) //(3) [undefined, undefined, undefined]
//map always try to return somethings if we don't return we get undefined.

//map is used for modification,copy of array.
//copy of array using map
const newNames= names.map(function(name){
return name;
})
Comment

map in javascript

const arr = [1, 2, 3, 4, 5, 6];
const mapped = arr.map(el => el + 20);	//[21, 22, 23, 24, 25, 26]
Comment

map js

const arr = [1,2,3,4,5]

const modifiedArr = arr.map((val) => {    // takes callback and returns modified array
	return val * 5
})
// map doesn't modify original array!
// arr = [1,2,3,4,5]
// modifiedArr = [5,10,15,20,25]
Comment

javascript map

const numbers = [2, 4, 6, 8];
const result = numbers.map(a => a * 2);
console.log(result);
//Output: [ 4, 8, 12, 16 ]
Comment

map method

function map(array, transform) {
  let mapped = [];
  for (let element of array) {
    mapped.push(transform(element));
  }
  return mapped;
}

let rtlScripts = SCRIPTS.filter(s => s.direction == "rtl");
console.log(map(rtlScripts, s => s.name));
// → ["Adlam", "Arabic", "Imperial Aramaic", …]
Comment

map in javascript

['elem', 'another', 'name'].map((value, index, originalArray) => { 
  console.log(.....)
});
Comment

map in javascript

let myMap = new Map()

let keyString = 'a string'
let keyObj    = {}
// setting the values
myMap.set(keyString, "value associated with 'a string'")
myMap.set(keyObj, 'value associated with keyObj')
myMap.set(keyFunc, 'value associated with keyFunc')
myMap.size              // 3
// getting the values
myMap.get(keyString)    // "value associated with 'a string'"
myMap.get(keyObj)       // "value associated with keyObj"
myMap.get(keyFunc)      // "value associated with keyFunc"
Comment

map javascript

var miMapa = new Map();

var claveObj = {},
    claveFunc = function () {},
    claveCadena = "una cadena";

// asignando valores
miMapa.set(claveCadena, "valor asociado con 'una cadena'");
miMapa.set(claveObj, "valor asociado con claveObj");
miMapa.set(claveFunc, "valor asociado with claveFunc");

miMapa.size; // 3

// obteniendo los valores
miMapa.get(claveCadena);    // "valor asociado con 'una cadena'"
miMapa.get(claveObj);       // "valor asociado con claveObj"
miMapa.get(claveFunc);      // "valor asociado con claveFunc"

miMapa.get("una cadena");   // ""valor asociado con 'una cadena'"
                         // porque claveCadena === 'una cadena'
miMapa.get({});           // undefined, porque claveObj !== {}
miMapa.get(function() {}) // undefined, porque claveFunc !== function () {}

var myMap = new Map();
myMap.set("bar", "foo");

myMap.delete("bar"); // Retorna true. Eliminado con éxito.
myMap.has("bar");    // Retorna false. El elemento "bar" ya no está presente.
Comment

map javascript

var numbers = [1, 4, 9];
var doubles = numbers.map(function(num) {
  return num * 2;
});
// doubles é agora [2, 8, 18]. numbers ainda é [1, 4, 9]
Comment

map function in js

var array = "M 175 0 L 326.55444566227675 87.50000000000001 L 326.55444566227675 262.5 L 175 350 L 23.445554337723223 262.5 L 23.44555433772325 87.49999999999999 L 175 0".split(" ");

let neWd = array.map(x => {
	if (x === 'M' || x === 'L'){
		return x;
	}else{
		return x * 2;
	}
}).join(' ')

console.log(neWd);
Comment

map javascript

test.map(x=> x)
Comment

map javascript

var kvArray = [["clave1", "valor1"], ["clave2", "valor2"]];

// El constructor por defecto de Map para transforar un Array 2D (clave-valor) en un mapa
var miMapa = new Map(kvArray);

miMapa.get("clave1"); // devuelve "valor1"

// Usando la función Array.from para transformar el mapa a un Array 2D clave-valor.
console.log(Array.from(miMapa)); // Muestra exactamente el mismo Array que kvArray

// O usando los iteradores de claves o valores y convirtiendo a array.
console.log(Array.from(miMapa.keys())); // Muestra ["clave1", "clave2"]
Comment

map values js

function mapValues(value, oldRange, newRange) {
    var newValue = (value - oldRange[0]) * (newRange[1] - newRange[0]) / (oldRange[1] - oldRange[0]) + newRange[0];
    return Math.min(Math.max(newValue, newRange[0]) , newRange[1]);
}
Comment

javascript map

// Creating javascript map with one instruction
const map = new Map([
  ["key", "value"],
  ["key2", "value2"],
]);
Comment

JavaScript map

function square(arr) {
       const newArr = arr.map(x => x * x );
    return newArr ;
  
  //if you find this answer is useful ,
//upvote ⇑⇑ , so can the others benefit also . @mohammad alshraideh ( ͡~ ͜ʖ ͡°)
Comment

JavaScript Map Function

const myAwesomeArray = [5, 4, 3, 2, 1]

myAwesomeArray.map(x => x * x)

// >>>>>>>>>>>>>>>>> Output: [25, 16, 9, 4, 1]
Comment

JS map

// Arrow function
map((element) => { /* … */ })
map((element, index) => { /* … */ })
map((element, index, array) => { /* … */ })

// Callback function
map(callbackFn)
map(callbackFn, thisArg)

// Inline callback function
map(function(element) { /* … */ })
map(function(element, index) { /* … */ })
map(function(element, index, array){ /* … */ })
map(function(element, index, array) { /* … */ }, thisArg)
Comment

javaScript Map() Method

// Create a Map
const fruits = new Map([
  ["apples", 500],
  ["bananas", 300],
  ["oranges", 200]
]);
Comment

javascript map

Shorthand: (key,value) Map 

const callbackMap = new Map<string, PushEventCallback>([
      ["addComment", addCommentCallback],
      ["commentModified", editCommentCallback]
]);

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map#:~:text=Cloning%20and%20merging%20Maps
Comment

map javascript

//forEach vs. Map High Order Array Methods
const arr = [1,2,3]
const arr2 = [...arr,4,5]//see spread operator grepper answer for [...arr]
//the forEach doesn't return anything, it just loops through the array
arr2.forEach(function(item) {
  console.log(item + ' of ' + arr2.length)
})
//map allows us to return an array and store it into a new array
const arr3 = arr2.map(function(item) {
  //after performing some operation on all the objects of the array
  //we can then return all those values into a new array
  return item * 2
})

console.log(arr3)

Comment

js map()

var number = [1, 2 , 3, 4, 5, 6, 7, 8, 9]; 
var doubles  = number.map((n) => { return n*2 })

/*  doubles 
    (9) [2, 4, 6, 8, 10, 12, 14, 16, 18] */
Comment

map javascript

// use the map method on an array.

// define array
let scores = [10, 25, 30]

// use of map, we store the map method in to a variable called doubledScore
let doubledScore = scores.map(function(score) {
	return score * 2 // returns every value of the array * 2 
})


console.log(doubledScore) // [20, 50, 60]
Comment

js Map

const result = new Map();//create a new map

result.set('a', 1);
result.set('b', 2);
console.log(result);

const germany = {name: 'Germany' , population: 8000000};//create a new object
result.set(germany, '80m');//set the object to the map

console.log(result);

result.delete('a');//delete the key 'a'
console.log(result);
result.clear();//clear all the keys in the map
console.log(result);
Comment

javascript map

const originals = [1, 2, 3];

const doubled = originals.map(item => item * 2);

console.log(doubled); // [2, 4, 6]
Comment

js map

const postIds = posts.map((post) => post.id);
Comment

map function javascript

var rebels = pilots.filter(function (pilot) {  return pilot.faction === "Rebels";});var empire = pilots.filter(function (pilot) {  return pilot.faction === "Empire";});
Comment

map method

var yourArray= yourArray.map(Number);
Comment

map method in javascript

const colorData = ['red','blue','green']
const result = colorData.map((el)=>el)
console.log(result)
Comment

map method

//// Write a function that takes an array of objects (courses) and returns object of 2 new arrays // first one is containing the names of all of the courses in the data set. // second one is containing the names of all the students
const getInfo = (arr) => {
  let coursesName = [];
  let studentsName = [];
  // write your code here

  return { coursesName, studentsName };
};

//if you find this answer is useful ,
//upvote ⇑⇑ , so can the others benefit also . @mohammad alshraideh ( ͡~ ͜ʖ ͡°)
Comment

js array map

let A = [9000, 8500, 5500, 6500];
let B = A.map(function (value, index, array) {
    return value*2; // forEach 沒有在 return 的,所以不會有作用
});
console.log(B); // undefined
Comment

Array.map method

const shoppingList = ['Oranges', 'Cassava', 'Garri', 'Ewa', 'Dodo', 'Books']

export default function List() {
  return (
    <>
      {shoppingList.map((item, index) => {
        return (
          <ol>
            <li key={index}>{item}</li>
          </ol>
        )
      })}
    </>
  )
}
Comment

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