Jak używać metody map w JavaScript
const numbers = [1, 2, 3, 4, 5];
const bigNumbers = numbers.map(number => {
return number * 10;
});
TechWhizKid
const numbers = [1, 2, 3, 4, 5];
const bigNumbers = numbers.map(number => {
return number * 10;
});The map() method creates a new array populated with the results of calling
a provided function on every element in the calling array.
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]//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
});let arr = [1,2,3]
/*
map accepts a callback function, and each value of arr is passed to the
callback function. You define the callback function as you would a regular
function, you're just doing it inside the map function
map applies the code in the callback function to each value of arr,
and creates a new array based on your callback functions return values
*/
let mappedArr = arr.map(function(value){
return value + 1
})
// mappedArr is:
> [2,3,4]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] */const items = [1, 2, 3, 4, 5, 6, 7, 8, 9];
const anotherItems = items.map(item => item * 2);
console.log(anotherItems);