JavaScript JavaScript and the DOM Getting a Handle on the DOM Selecting Multiple Elements

Gonzalo Torres del Fierro
Gonzalo Torres del Fierro
Pro Student 16,741 Points

We have some JavaScript code that will cycle over list items and apply colors from an array called colors. The code will

I have a question here, this is my answer:

<!DOCTYPE html>
    <ul id="rainbow">
      <li>This should be red</li>
      <li>This should be orange</li>
      <li>This should be yellow</li>
      <li>This should be green</li>
      <li>This should be blue</li>
      <li>This should be indigo</li>
      <li>This should be violet</li>
    <script src="js/app.js"></script>
let listItems = document.querySelectorAll('li:nth-child(odd)');
const colors = ["#C2272D", "#F8931F", "#FFFF01", "#009245", "#0193D9", "#0C04ED", "#612F90"];

for(var i = 0; i < colors.length; i ++) {
  listItems[i].style.color = colors[i];    
Gonzalo Torres del Fierro
Gonzalo Torres del Fierro
Pro Student 16,741 Points

the right answer is : let listItems = document.querySelectorAll('li');

but why is not possible to use my solution?

let listItems = document.querySelectorAll('li:nth-child(odd)');

1 Answer

Jennifer Nordell
Jennifer Nordell
Treehouse Staff

Hi there, Gonzalo Torres del Fierro ! Your code is selecting only the odd list item elements. It will return the list items containing "red", "yellow", "blue", and "violet". The challenge is asking you to select all list items because we want to run that loop over all of them, not just 4 of 7.

Hope this helps! :sparkles:

edited for additional information

The reason for the undefined error is because the for loop is running until colors is exhausted, but it contains 7 colors while your selector results in a total of 4 items. At the point where you reach the 5th color, i will be out of bounds for the listItems. Take a look under the "Preview" button and see the results. Note that the colors don't match the descriptions :smiley: