Arrays
Array are container-like values that can hold other values. The values inside an array are called elements.
EXAMPLE |
---|
var breakfast = ["coffee", "croissant"]; breakfast; |
OUTPUT |
["coffee", "croissant"] |
Array elements don’t all have to be the same type of value. Elements can be any kind of JavaScript value — even other arrays.
EXAMPLE |
---|
var hodgepodge = [100, "paint", [200, "brush"], false]; hodgepodge; |
OUTPUT |
[100, "paint", [200, "brush"], false] |
Accessing Elements
To access one of the elements inside an array, you’ll need to use the brackets and a number like this: myArray[3]. JavaScript arrays begin at 0, so the first element will always be inside [0].
EXAMPLE |
---|
var sisters = ["Tia", "Tamera"]; sisters[0]; |
OUTPUT |
"Tia" |
To get the last element, you can use brackets and `1` less than the array’s length property.
EXAMPLE |
---|
var actors = ["Felicia", "Nathan", "Neil"]; actors[actors.length - 1]; |
OUTPUT |
"Neil" |
This also works for setting an element’s value.
EXAMPLE |
---|
var colors = ["red", "yelo", "blue"]; colors[1] = "yellow"; colors; |
OUTPUT |
["red", "yellow", "blue"] |
Properties and methods
Arrays have their own built-in variables and functions, also known as properties and methods. Here are some of the most common ones.
length
An array’s length property stores the number of elements inside the array.
EXAMPLE |
---|
["a", "b", "c", 1, 2, 3].length; |
OUTPUT |
6 |
concat
An array’s concat method returns a new array that combines the values of two arrays.
EXAMPLE |
---|
["tortilla chips"].concat(["salsa", "queso", "guacamole"]); |
OUTPUT |
["tortilla chips", "salsa", "queso", "guacamole"] |
pop
An array’s pop method removes the last element in the array and returns that element’s value.
EXAMPLE |
---|
["Jupiter", "Saturn", "Uranus", "Neptune", "Pluto"].pop(); |
OUTPUT |
"Pluto" |
push
An array’s push method adds an element to the array and returns the array’s length.
EXAMPLE |
---|
["John", "Kate"].push(8); |
OUTPUT |
3 |
reverse
An array’s reverse method returns a copy of the array in opposite order.
EXAMPLE |
---|
["a", "b", "c"].reverse(); |
OUTPUT |
["c", "b", "a"] |
Ready to learn more?
Become a Javascript developer at your own pace!
When you sign up with Pluralsight, you'll immediately have access to thousands of expert courses, paths to guide your learning, tools to measure your skills and hands-on resources like exercise files. Javascript is just the beginning. There’s no limit on what you can learn and you can cancel at any time.