Rounding problem with parseFloat

@xmike1Mar 28.2005

I am having trouble when doing simple addition on strings I convert with parseFloat(). If I take 125.99 + 0.99 I get 126.97. This does not always behave this way. If I take 125.99 + 0.98 I get 126.97. The numbers are in a group of text fields, with the same name, on an HTML form. As I go through this input field array I add each number to the current accumulated total. Any direction would be appreciated.

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JavaScript

@Warren86Mar 28.2005 — #<HTML>

<Head>

<Script Language=JavaScript>

function calcSum(){
 
   isSum = 0;
   nVals = document.getElementsByName('toSum');
   for (i=0; i<nVals.length; i++)
   {isSum += parseFloat(nVals[i].value)}
   isSum = isSum.toFixed(2);
   document.forms.Form1.nSum.value = isSum;
  }

</Script>

</Head>

<Body>

<Form name='Form1'>

<input type=text value='126.99' name='toSum' size='7'><br>

<input type=text value='.99' name='toSum' size='7'><br>

<input type=text value='125.98' name='toSum' size='7'><br>

<input type=text value='1.90' name='toSum' size='7'><br>

<input type=text value='.98' name='toSum' size='7'><br><br>

Sum: <input type=text name='nSum' size='7'>

</Form>

<input type=button value='Test' onclick="calcSum()">

</Body>

</HTML>

@js_prof_consMar 28.2005 — #I am having trouble when doing simple addition on strings I convert with parseFloat(). If I take 125.99 + 0.99 I get 126.97. This does not always behave this way. If I take 125.99 + 0.98 I get 126.97. The numbers are in a group of text fields, with the same name, on an HTML form. As I go through this input field array I add each number to the current accumulated total. Any direction would be appreciated.[/QUOTE]This has to do with the fact that reals are inaccurate. That's why large scale corporations use Integers to do everything. For example, your problem:

125.99 * 100 =&gt; 12599
 0.99 * 100 =&gt; [u] +   99[/u]
 12698 / 100 =&gt; 126.98

@xmike1authorMar 28.2005 — #Thanks folks. Both of these work just fine. Much appreciated.

@js_prof_consMar 28.2005 — #Thanks folks. Both of these work just fine. Much appreciated.[/QUOTE]I forgot to give an example of such a corpoartion. One off the top of my head is NASA.

@blkfdMay 16.2005 — #I am not a java programer but tend to cut and paste java when I need to. I've been looking for simple code to sum two number fields which exactly what you've posted here. It does just what I need except I need to capture the number fields so they need to have unique names like (toSum1 + toSum2). Can I do that by modifying this code?

Thanks,

Joe

Rounding problem with parseFloat

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