The JavaScript spread operator (... ) allows us to quickly copy all or part of an existing array or object into another array or object.
const numbersOne = [1, 2, 3];
const numbersTwo = [4, 5, 6];
const numbersCombined = [...numbersOne, ...numbersTwo];The spread operator is often used in combination with destructuring.
Assign the first and second items from numbers to variables and put the rest in an array:
const numbers = [1, 2, 3, 4, 5, 6];const [one, two, ...rest] = numbers;We can use the spread operator with objects too:
const car = {
brand: 'Ford', model: 'Mustang', color: 'red'
}const car_more = {
type: 'car', year: 2021, color: 'yellow'
}const mycar = {...car, ...car_more}Notice that the properties that did not match were added, and the property that did match was overwritten by the last object.