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JavaScript

Posted by Ben Os
Ben Os
20,008 Points

document.getElementsByClassName('header').style.backgroundColor = 'red';

document.getElementsByClassName('header').style.backgroundColor = 'red';

I went to the Firefox console trying to change the background color of the Treehouse.com header.

The tag is header and it's class is also header.

I used this code but I keep getting "type error: style is undefined".

1 Answer

Joe Beltramo
Joe Beltramo
22,311 Points

When you use the method getElementsByClassName you are requesting an array of items. style is a property against a single element. I would suggest trying to reference the element you wish by first selecting it by it's index in the array you are given.

I.E.

document.getElementsByClassName('header')[0].style.backgroundColor = 'red'