Two decimal places only

pallone · #1 (**permalink**) January 23rd, 2005, 07:31 PM

Hi,

I can not figure ou what is happening in this code. If I multiply 3.99 * 5 I am getting 19.950000000000003. So I get lots of places after the decimal point. Now if I multiply by 3 I get only two decimal places 3.99 * = 11.97

also, the Total field of my table is not behaving the way I want. Sometimes I get lots of places and sometimes only two decimal places.

Could someone please help me to sort this out. I would like to give the user the choice to choose only two decimal places or three..

Please run the code below to see what the problem is.

The code:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
    <head>
        <title></title>
        <meta name="GENERATOR" content="Microsoft Visual Studio .NET 7.1">
        <meta name="ProgId" content="VisualStudio.HTML">
        <meta name="Originator" content="Microsoft Visual Studio .NET 7.1">
        <style>
            H1, P {font-family:verdana}
            TH {font-family:verdana; text-align:center}
            TD {font-family:verdana; text-align:left}
            INPUT {font-family:verdana; text-align:right}
        </style>

        <script type="text/javascript">
        
        </script>
    </head>
    <body>
        <form method="post" action="AddMultiply.htm" name="orderform">
            <TABLE WIDTH="552" BORDER="1" CELLSPACING="1" CELLPADDING="0">
                <TR>
                    <TH width="54">
                        Quantity</TH>
                    <TH width="101">
                        Product ID</TH>
                    <TH width="106">
                        Description</TH>
                    <TH width="100">
                        Unit Price</TH>
                    <TH width="100">
                        SubTotal</TH>
                </TR>
                <TR>
                    <TD width="54"><input type="text" name="intqty1" size="7" value="5"></TD>
                    <TD width="101">101-abc</TD>
                    <TD width="106">Perfume</TD>
                    <TD width="100">3.99</TD>
                    <TD width="100"><input type="text" name="intsub1" size="12" value=""></TD>
                </TR>
                <TR>
                    <TD width="54"><input type="text" name="intqty2" size="7" value="1"></TD>
                    <TD width="101">234rf</TD>
                    <TD width="106">Photo</TD>
                    <TD width="100">15.99</TD>
                    <TD width="100"><input type="text" name="intsub2" size="12" value=""></TD>
                </TR>
                <TR>
                    <TD width="54"><input type="text" name="intqty3" size="7" value="1"></TD>
                    <TD width="101">f98f</TD>
                    <TD width="106">Jar</TD>
                    <TD width="100">8.57</TD>
                    <TD width="100"><input type="text" name="intsub3" size="12" value=""></TD>
                </TR>
                <tr>
                    <td width="315" colspan="3">
                        <input type="button" value="Update order" name="cmdUpdate" style="text-align:center"
                         onclick="ReCalc()">
                    </td>
                    <td width="100">Total</td>
                    <td width="100"><input type="text" name="intTotal" size="12" value=""></td>
                </tr>
            </TABLE>
        </form>
    </body>
</html>

Vadivel · #2 (**permalink**) January 24th, 2005, 12:39 AM

Change the javascript function as follows:

function ReCalc()
{
var f = document.orderform;
f.intsub1.value = Number(parseInt(f.intqty1.value) * 3.99).toFixed(2);
f.intsub2.value = Number(parseInt(f.intqty2.value) * 15.99).toFixed(2);
f.intsub3.value = Number(parseInt(f.intqty3.value) * 8.57).toFixed(2);
f.intTotal.value = Number(parseFloat(f.intsub1.value) + parseFloat(f.intsub2.value) + parseFloat(f.intsub3.value)).toFixed(2);
}

Best Regards
Vadivel

MVP ASP/ASP.NET
http://vadivel.thinkingms.com

pallone · #3 (**permalink**) January 25th, 2005, 07:56 AM

Hi Vadivel,

Many thanks for your help. It is working now. I have just one more question:

1 - is it possible to force the number to round up or down ?

suppose the result of the multiplication is 13.55. How can I round it up to 13.6 or round down to 13.5??

Cheers,

Claudio

Vadivel · #4 (**permalink**) January 25th, 2005, 02:31 PM

For rounding off numbers make use of Math.round and Math.pow .. .check the below sample:

<html>
<head>
<script language="javascript">
function fnRound()
{
   var formField = document.frmTest.txtValue;
   var roundedValue = Math.round(formField.value*Math.pow(10,1))/Math.pow(10,1);
   formField.value = roundedValue;
}
</script>
</head>
<body>
<form name="frmTest">
   <input type="text" name="txtValue">
   <input type="button" value="Round" onClick="fnRound();">
</form>
</body>
</html>

Best Regards
Vadivel

MVP ASP/ASP.NET
http://vadivel.thinkingms.com

pallone · #5 (**permalink**) January 28th, 2005, 09:55 AM

Hi Vadivel,

Thanks ever so much for your help and sharing your knowledge with us in the forum. I have just tested the sample code you provided and it works fine.

Cheers,

Claudio
:)

Vadivel · #6 (**permalink**) February 2nd, 2005, 12:35 AM

Cool .. glad to know that my code was of help to you :)

Best Regards
Vadivel

MVP ASP/ASP.NET
http://vadivel.thinkingms.com

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