JavaScript Arrays: Create, Read and Loop Through Lists

Learn how to create JavaScript arrays, access items by index, add values and loop through a list with for...of.

Create an array

An array stores an ordered list of values. Each item has a zero-based index, so the first item is at index 0.

const colors = ["blue", "green", "orange"];

console.log(colors[0]); // "blue"
console.log(colors.length); // 3

Add or update items

Use push() to add an item to the end. Use an index when you need to replace an existing item.

colors.push("purple");
colors[1] = "teal";

Loop through a list

A for...of loop reads each value in order. It works well when you want to perform the same action for every item.

for (const color of colors) {
  console.log(color);
}