nodeName Problem

**AverageMax** · Jul 17, 2011 22:44

Hello,

I'm reading Simply JavaScript and I ran into a problem with an example from a book. I can't get nodeName to work properly. Am I doing something wrong?

Here's my code:

HTML Code:

<body>
  <h4 id="movieTitle">Analyze This</h4>

  <p>
    The film stars Robert De Niro as a mafioso and Billy Crystal as a psychiatrist.
  </p>
</body>

Code JavaScript:

var target = document.getElementById("movieTitle");
 
alert(target.nodeName);

Help me, please. Thank you in advance.

**Mittineague** · Jul 17, 2011 23:19

Hi AverageMax, welcome to the forums,

Just guessing. Is the javascript running before the page's DOM loads in?

**AverageMax** · Jul 17, 2011 23:26

I don't know. I'm just starting with JavaScript. How can I check that?

Thank you.

**Mittineague** · Jul 17, 2011 23:42

Well, there are a few ways things can be done.

If the javascript is in the <head> and isn't in a function that's called by onload (preferrably by adding an event listener to the body IMHO) or at the end of the page then the script runs before the page's DOM is loaded in so the tags won't be there yet to get. eg. this won't work:

HTML Code:

<html><head><title>nodeName test</title>
<script type='text/javascript'>
var target = document.getElementById("movieTitle");
alert(target.nodeName);
</script>
</head>
<body>
  <h4 id="movieTitle">Analyze This</h4>
  <p>
    The film stars Robert De Niro as a mafioso and Billy Crystal as a psychiatrist.
  </p>
</body></html>

but this will:

HTML Code:

<html><head><title>nodeName test</title>
</head>
<body>
  <h4 id="movieTitle">Analyze This</h4>
  <p>
    The film stars Robert De Niro as a mafioso and Billy Crystal as a psychiatrist.
  </p>
<script type='text/javascript'>
var target = document.getElementById("movieTitle");
alert(target.nodeName);
</script>
</body></html>

*a quick and dirty example, but hopefully it helps

**AverageMax** · Jul 17, 2011 23:49

My JavaScript is in an external file, but this works!

Thank you very much!

**paul_wilkins** · Jul 17, 2011 23:55

I agree, putting your script at the bottom is the best technique to speed up your web page and improve your ability to work with the DOM.

The Simply Scripting book uses its own custom library called Core, which includes a method called .start()
Pages 58 and 59 of the book cover that, in the section titled Unobtrusive Scripting in the Real World.

**AverageMax** · Jul 18, 2011 12:52

I must have missed it.

Thanks.

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