calculate sums to the 2nd decimal

chunk1978

hey... can anyone show me how to calculate sums to the 2nd decimal only? like:

5.50 + 4.00 = 9.50

i seriously have zero idea and could defo use some help...thanks!

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<script type="text/javascript">

<!--

function InvoiceSubTotal(form)

    {

    var a = (form.assignmentinvoice.value != '') ? eval(form.assignmentinvoice.value) : 0;

    var b = (form.printinginvoice.value != '') ? eval(form.printinginvoice.value) : 0;

    var c = (form.shippinginvoice.value != '') ? eval(form.shippinginvoice.value) : 0;

    form.invoicesubtotal.value = a + b + c;

}

//-->

</script>
 
</head>
 
<html>

<body>

<label></label>

<p>&nbsp;</p>

<form id="form" name="form" method="post" action="">

  <label>

  <input name="assignmentinvoice" type="text" id="assignmentinvoice" value="3.36" />

  </label>

  <p>

    <label>

    <input name="printinginvoice" type="text" id="printinginvoice" value="8.26" />

    </label>

  </p>

  <p>

    <label>

    <input name="shippinginvoice" type="text" id="shippinginvoice" value="89.22" />

    </label>

  </p>

  <p>

    <label>

    <input type="checkbox" name="checkbox" value="checkbox" onClick="InvoiceSubTotal(this.form);"/>

    </label>

  Click to Calculate! </p>

  <p>Total: 

    <label>

    <input name="invoicesubtotal" type="text" id="invoicesubtotal" />

    </label>

  </p>

</form>

<p>&nbsp;</p>

</body>

</html>

acoder

Use

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var result = num.toFixed(2);

where 2 is the number of decimal places.

chunk1978

Quote:

Originally Posted by acoder

Use

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var result = num.toFixed(2);

where 2 is the number of decimal places.

humm... i hope not like this... as this doesn't work... for sure it's way wrong... but am i close?

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function InvoiceSubTotal(form)

    {

    var a = (form.assignmentinvoice.value != '') ? eval(form.assignmentinvoice.value) : 0;

    var b = (form.printinginvoice.value != '') ? eval(form.printinginvoice.value) : 0;

    var c = (form.shippinginvoice.value != '') ? eval(form.shippinginvoice.value) : 0;

    var total = (form.invoicesubtotal.value = a + b + c);

    var result = num.toFixed(2);

    form.invoicesubtotal.value = total;

    form.invoicesubtotal.value = result;

}

acoder

Quote:

Originally Posted by chunk1978

humm... i hope not like this... as this doesn't work... for sure it's way wrong... but am i close?

Expand|Select|Wrap|Line Numbers

  
function InvoiceSubTotal(form)

    {

    var a = (form.assignmentinvoice.value != '') ? eval(form.assignmentinvoice.value) : 0;

    var b = (form.printinginvoice.value != '') ? eval(form.printinginvoice.value) : 0;

    var c = (form.shippinginvoice.value != '') ? eval(form.shippinginvoice.value) : 0;

    var total = (form.invoicesubtotal.value = a + b + c);

    var result = num.toFixed(2);

    form.invoicesubtotal.value = total;

    form.invoicesubtotal.value = result;

}

One mistake is in the following line:

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var total = (form.invoicesubtotal.value = a + b + c);

Change that to

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var total = a + b + c;

Also, num was only an example. Replace that with total. Why set the invoice subtotal to both total and then result. Just set it to result.

One final thing: don't use eval. Use parseFloat instead:

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 var a = (form.assignmentinvoice.value != '') ? parseFloat(form.assignmentinvoice.value) : 0;
 

parseFloat will return NaN if not a number. In that case check using isNaN:

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if (isNaN(a)) a = 0;

or you could just include it when setting a, b, and c if you like your cryptic coding!

One final, final thing is that in your original post, your html is incorrect. The Javascript goes in the head section but html comes before head like:
[HTML]<html>
<head>
...
</head>
<body>
...
</body>
</html>[/HTML]

chunk1978

ok... so this is what i have now, but it's still not working :-/

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<html>

<head>

<script type="text/javascript">

<!--

function InvoiceSubTotal(form)

    {

    var a = (form.assignmentinvoice.value != '') ? parseFloat(form.assignmentinvoice.value) : 0; if (isNaN(a)) a = 0;

    var b = (form.printinginvoice.value != '') ? parseFloat(form.printinginvoice.value) : 0; if (isNaN(b)) b = 0;

    var c = (form.shippinginvoice.value != '') ? parseFloat(form.shippinginvoice.value) : 0; if (isNaN(c)) c = 0;

    var total = a + b + c;

    form.invoicesubtotal.value = total;

    total.toFixed(2);

}

//-->

</script>
 
</head>
 
<body>

<label></label>

<p>&nbsp;</p>

<form id="form" name="form" method="post" action="">

  <label>

  <input name="assignmentinvoice" type="text" id="assignmentinvoice" value="3.356" />

  </label>

  <p>

    <label>

    <input name="printinginvoice" type="text" id="printinginvoice" value="8.26" />

    </label>

  </p>

  <p>

    <label>

    <input name="shippinginvoice" type="text" id="shippinginvoice" value="89.2554332" />

    </label>

  </p>

  <p>

    <label>

    <input type="checkbox" name="checkbox" value="checkbox" onClick="InvoiceSubTotal(this.form);"/>

    </label>

  Click to Calculate! </p>

  <p>Total: 

    <label>

    <input name="invoicesubtotal" type="text" id="invoicesubtotal" />

    </label>

  </p>

</form>

<p>&nbsp;</p>

</body>

</html>

thanks for the help acoder... i always do appreciate it...

chunk1978

ouf! nevermind... i got it! woo hoo! :-D

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<script type="text/javascript">

<!--

function InvoiceSubTotal(form)

    {

    var a = (form.assignmentinvoice.value != '') ? parseFloat(form.assignmentinvoice.value) : 0; if (isNaN(a)) a = 0;

    var b = (form.printinginvoice.value != '') ? parseFloat(form.printinginvoice.value) : 0; if (isNaN(b)) b = 0;

    var c = (form.shippinginvoice.value != '') ? parseFloat(form.shippinginvoice.value) : 0; if (isNaN(c)) c = 0;

    var total = a + b + c;

    form.invoicesubtotal.value = total.toFixed(2)
 
}

//-->

</script>

calculate sums to the 2nd decimal

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