React ES6 Spread Operator
Spread Operator
The JavaScript spread operator (...) allows us to quickly copy all or part of an existing array or object into another array or object.
Example
const numbersOne = [1, 2, 3];
const numbersTwo = [4, 5, 6];
const numbersCombined = [...numbersOne, ...numbersTwo];The spread operator is often used in combination with destructuring.
Example
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:
Example
Combine these two objects:
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.
