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JavaScript Interactive Web Pages with JavaScript Traversing and Manipulating the DOM with JavaScript Traversing Elements

Xinqi Li
Xinqi Li
3,065 Points
Posted by Xinqi Li
Xinqi Li
3,065 Points

'length' does not work when using .children()

I used var listItems = navigation.children(); but when I get the length of listItems, it says 'undefined' is not an object (evaluating 'listItems.length')

app.js 
//Select the navigation
var navigation = document.getElementById("navigation");

//Select all listItems from the navigation
var listItems = navigation.children();

//When a navigation link is pressed
var linkListener = function() {
  console.log("Listener is clicked!");
}

var bindEventsToLinks = function(listItem) {
  //Select the anchor
  var anchor = listItem;
  //Bind the linkListener to the anchor element (a) 
  anchor.onclick = linkListener;
}

for(var i = 0; i < listItems.length ; i++) {
    bindEventsToLinks(listItems[i]);
}
index.html 
<!DOCTYPE html>
<html>
<head></head>
<body>

<ul id="navigation">
  <li>
    <a href="#home">Home</a>
  </li>
  <li>
    <a href="#about">About</a>
  </li>
  <li>    
    <a href="#contact">Contact</a>
  </li>
</ul>

<p>A few of my favourite things:</p>
<ul>
  <li>
    Rain drops on roses
  </li>
  <li>
    Whiskers on kittens
  </li>
  <li>
    Brown paper packages wrapped up with string
  </li>
</ul>

<script src="app.js"></script>
</body>
</html>

1 Answer

David Bath
David Bath
25,940 Points
David Bath
David Bath
25,940 Points

children() is a jQuery method. You need to just use the children property.