Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Using Array Indices

Do negative indices work in JavaScript?

I'm new to JavaScript but have some experience in other languages. Isn't it possible to grab the last index using -1? It failed me here....

script.js
var players = ['Jim', 'Shawna', 'Andrew', 'Lora', 'Aimee', 'Nick'];
console.log(players[0]);
console.log(players[-1]);
index.html
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript Loops</title>
</head>
<body>
<script src="script.js"></script>
</body>
</html>

1 Answer

Yes, there's a few ways to get the last item in an array.

An array index starts at 0, but the length will return 6.

The length property of an array does not start off on the 0 index. Therefore, if you type console.log(players[players.length]) it will come back undefined because there's nothing at index 6. Index stops at 5.

With that in mind you can use the example below.

console.log(players[players.length - 1]);