React

What is ES6?

ES6 stands for ECMAScript 6.

ECMAScript was created to standardize JavaScript, and ES6 is the 6th version of ECMAScript, it was published in 2015, and is also known as ECMAScript 2015.

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 myVehicle = {
  brand: 'Ford',
  model: 'Mustang',
  color: 'red'
}

const updateMyVehicle = {
  type: 'car',
  year: 2021, 
  color: 'yellow'
}

const myUpdatedVehicle = {...myVehicle, ...updateMyVehicle}

Notice the properties that did not match were combined, but the property that did match, color, was overwritten by the last object that was passed, updateMyVehicle. The resulting color is now yellow.