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

Posted by Brendan Dzeguze
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Brendan Dzeguze
Front End Web Development Techdegree Graduate 14,567 Points

My code isnt running.

The site says TypeError: 'undefined' is not an object(evaluating 'listitems[i].style'). what is going on? can someone help me?

js/app.js 
var listItems = document.getElementById('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
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PLUS
.a{fill-rule:evenodd;}techdegree seal-36
Rabin Gharti Magar
Front End Web Development Techdegree Graduate 20,928 Points
Rabin Gharti Magar
.a{fill-rule:evenodd;}techdegree seal-36
Rabin Gharti Magar
Front End Web Development Techdegree Graduate 20,928 Points

Hey Brendan Dzeguze,

getElementById() method returns a single element object. You can use querySelectorAll() method which returns a node list.

In the following code I have used querySelectorAll() method followed by a descendant selector to select its children <li> elements.

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];    
}

Hope this helps!