Answers for "javascript map"

46

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 }; });
Posted by: Guest on October-01-2020
24

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]
Posted by: Guest on November-25-2019
0

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"]
Posted by: Guest on February-11-2021
4

javascript map

The map() method creates a new array with the results of calling a provided function on every element in the calling array.
Posted by: Guest on December-22-2019
-2

map javascript

miMapa.forEach(function(valor, clave) {
  console.log(clave + ' = ' + valor);
});
// Mostrará 2 logs; el primero con "0 = cero" y el segundo con "1 = uno"
Posted by: Guest on February-11-2021

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