Here are some ways that you can add more data to an array in JavaScript.

1. Use array push()

Array push() allows you to add new items to the end of the array

Examples below:

Add an item

const superCars = ["McLaren", "Ferrari", "Lamborghini", "Audi R8"];
superCars.push("Aston Martin");
console.log(superCars);

Add multiple items

const superCars = ["McLaren", "Ferrari", "Lamborghini", "Audi R8"];
superCars.push("Aston Martin", "Bugatti");
console.log(superCars);

2. Use array unshift()

Array unshift() allows you to add new items to the beginning of the array

Examples below:

Add an item

const superCars = ["McLaren", "Ferrari", "Lamborghini", "Audi R8"];
superCars.unshift("Aston Martin");
console.log(superCars);

Add multiple items

const superCars = ["McLaren", "Ferrari", "Lamborghini", "Audi R8"];
superCars.unshift("Aston Martin", "Bugatti");
console.log(superCars);

3. Use Spread syntax(…)

Spread syntax(…) allows the array to expand. However, not within the array itself. It takes the old array and creates a new one with the new items added.

Unlike push() or unshift(), with Spread syntax(…), you are able to add items at either end of an array.

Example below:

Add items at beginning

const superCars = ["McLaren", "Ferrari", "Lamborghini", "Audi R8"];

const newSuperCars = [
  "Aston Martin",
  "Bugatti",
  ...superCars
];

Add items at end

const superCars = ["McLaren", "Ferrari", "Lamborghini", "Audi R8"];

const newSuperCars = [
  ...superCars,
  "Aston Martin",
  "Bugatti"
];