Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Using For Loops with Arrays

Posted by Iliya Narsiya
Iliya Narsiya
3,387 Points

Using For Loops with Arrays

why in the square brackets located i ?.

function printList( list ) { var listHTML = '<ol>'; for (var i = 0; i < list.length; i += 1) { listHTML += '<li>' + list[i] + '</li>'; }

1 Answer

Bryan Lam
Bryan Lam
15,592 Points
Bryan Lam
Bryan Lam
15,592 Points

"i" is the counter variable that the 'for loop' increases every time it goes through each loop.

The list[i] tells which element of the array the code will execute.

For example, on the first loop the "i" counter is equal to 0 so the code will print out the value of list[0].

Then on the next loop, since the "i" variable is increased by one (due to "i += 1", in the for loop condition) and the code will print out the value in list[1].

That is why there's an "i" in the square brackets.

Iliya Narsiya
Iliya Narsiya
3,387 Points

Thanks!