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JavaScript JavaScript and the DOM (Retiring) Getting a Handle on the DOM Selecting Multiple Elements

Posted by Jonathan Ambriz
Jonathan Ambriz
Courses Plus Student 3,902 Points

Need help understaind document.querySelectorAll. That selects for the Id, but it doesn't allow the for loop to iterate.

The querySelectorAll selects the Id of '#rainbow', but it doesn't iterate past the red color in the array of colors. What am I missing? Should I make all the <li> have the Id of 'rainbow' as well?

js/app.js 
var listItems = document.querySelectorAll('#rainbow');
var colors = ["#C2272D", "#F8931F", "#FFFF01", "#009245", "#0193D9", "#0C04ED", "#612F90"];

for(var i = 0; i < colors.length; i ++) {
  listItems[i].style.color = colors[i];    
}
index.html 
<!DOCTYPE html>
<html>
  <head>
    <title>Rainbow!</title>
  </head>
  <body>
    <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>
    </ul>
    <script src="js/app.js"></script>
  </body>
</html>

1 Answer

Rabin Gharti Magar
.a{fill-rule:evenodd;}techdegree seal-36
Rabin Gharti Magar
Front End Web Development Techdegree Graduate 20,937 Points

Hey Jonathan Ambriz,

There are two ways to solve this challenge. I will go through them both.

  1. You can use document.querySelectorAll method to select the id rainbow and then use a descendant selector to select its children.

  2. Or you could use document.querySelector method to select <ul> element with the id of rainbow and use children property to select its children .

Both of these above methods will return the same results.

document.querySelector() method

var listItems = document.querySelector('#rainbow').children;
var colors = ["#C2272D", "#F8931F", "#FFFF01", "#009245", "#0193D9", "#0C04ED", "#612F90"];

for(var i = 0; i < colors.length; i ++) {
  listItems[i].style.color = colors[i];    
}

document.querySelectorAll() method

var listItems = document.querySelectorAll('#rainbow li');
var colors = ["#C2272D", "#F8931F", "#FFFF01", "#009245", "#0193D9", "#0C04ED", "#612F90"];

for(var i = 0; i < colors.length; i ++) {
  listItems[i].style.color = colors[i];    
}

To learn more about children property, check out this website: https://developer.mozilla.org/en-US/docs/Web/API/ParentNode/children

Hope this helps!