Arrrrg!!! "undefinded" and then "NaN" Help?

**PHP John** · May 6, 2003, 19:29

In the code below I have a variable called (uncreatively enough) "number". This variable is supposed to be incremented every 2 seconds, and as a test I "alert" it out to the screen.

However, the first alert says "undefined", and all subsequent alerts say "NaN".

I'm fairly new to JavaScript, but not to programming. I declare and initialize it in the head, and then increment it in the function. I have tried placing the declaration in the function, thinking it might be a scope problem, but I get the same alerts.

Any boot in the right direction would be greatly appreciated!

PHP Code:


<html>
  <head>
    <title>Campaign Promises for 2004</title>
    <link href="style.css" rel="stylesheet" type="text/css">

    <script language="javascript" type="text/javascript">
      <!--
        var dollars = new array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ",", ":", "$");
        var number = 9999;
        function window_onload()
        {
          window.setInterval("updateDollars()", 2000);
        }
      -->
    </script>

  </head>
  <body language="javascript" onload="return window_onload();">
    <div align="center">
      <table width="750" border="1">
        <tr>
          <td>
      <table width="750" border="0" cellpadding="0" cellspacing="0" summary="page table">
        <tr>
          <td colspan="5" height="50" background="graphics/logo.gif">
            &nbsp;
          </td>
        </tr>
        <tr class="nav" valign="top">
          <td height="20" width="375" background="graphics/timeBar.gif">
            <span class="moneySpent">Money Spent: $</span>
            <img name="1" src="graphics/placeHolder.gif">

            <script language="javascript" type="text/javascript">
              <!--
                var startDollars = 10000000;
                function updateDollars()
                {
                  alert('number = ' + number);
                  number++;
                  if( number > 9 ) number = 0;
                }
              -->
            </script>

          </td>
          <td align="center">
            nav
          </td>
          <td align="center">
            nav
          </td>
          <td align="center">
            nav
          </td>
          <td align="center">
            nav
          </td>
        </tr>
        <tr height="15">
          <td colspan="5" background="graphics/logoUnderbar.gif">
          </td>
        </tr>
      </table>
          </td>
        </tr>
      </table>
    </div>
  </body>
</html>

**Drew630** · May 7, 2003, 07:30

Well, you were right about the scope. What it is, since you seperated your functions into different areas, the number variable was defined once, then lost all definition once the scope was left from the head area. What I did was pass number to your function for updating dollars. It gets rid of the alert errors, but I am not sure exactly what this code is meant to do, so I don't know if it is behaving the eay you want. If not, post again and I'll take a look.

Here's the fixed code.

Code:

<html>
  <head>
	<title>Campaign Promises for 2004</title>
	<link href="style.css" rel="stylesheet" type="text/css">
	<script language="javascript" type="text/javascript">
	  <!--
		var dollars = new Array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ",", ":", "$" );
		var number = 9999;
		function window_onload()
		{
		  window.setInterval("updateDollars(number)", 2000);
		}
	  -->
	</script>
  </head>
  <body language="javascript" onload="return window_onload();">
	<div align="center">
	  <table width="750" border="1">
		<tr>
		  <td>
	  <table width="750" border="0" cellpadding="0" cellspacing="0" summary="page table">
		<tr>
		  <td colspan="5" height="50" background="graphics/logo.gif">
			&nbsp;
		  </td>
		</tr>
		<tr class="nav" valign="top">
		  <td height="20" width="375" background="graphics/timeBar.gif">
			<span class="moneySpent">Money Spent: $</span>
			<img name="1" src="graphics/placeHolder.gif">
	<script language="javascript" type="text/javascript">
	  <!--
	 var startDollars = 10000000;
	 function updateDollars(number)
	 {
	   alert('number = ' + number);
	   number++;
	   if( number > 9 ) number = 0;
	 }
	  -->
	</script>
		  </td>
		  <td align="center">
			nav
		  </td>
		  <td align="center">
			nav
		  </td>
		  <td align="center">
			nav
		  </td>
		  <td align="center">
			nav
		  </td>
		</tr>
		<tr height="15">
		  <td colspan="5" background="graphics/logoUnderbar.gif">
		  </td>
		</tr>
	  </table>
		  </td>
		</tr>
	  </table>
	</div>
  </body>
</html>

Drew

**BenANFA** · May 7, 2003, 07:32

Actually this is php not JavaScript

PHP Code:


        var dollars = new array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ",", ":", "$" );

this is the JavaScript mannor of defining an array

PHP Code:


        var dollars = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ",", ":", "$" ];

This is the only problem in your code fix this and it works. This is beacuse the error stops the JavaScript parser from processing the next line so the variable number is not created.

If your using IE as your test bed switch off "disable script debugging" while you are developping, it catches this error.