JavaScript - Help With Rounding

Hi..

I have javascript code with computation, but I have problem in my result because it was not round off or fixed into two decimal places only.

here is my code:

Code:

<script type="text/javascript">

function test_(cmpd) {
    var len_ = (document.frmMain.elements.length) - 1;
  
     for (i=0; i <= len_; i++ ) {   
    
       var strPos_ = document.frmMain.elements[i].id.indexOf(cmpd)
         
   
              if (strPos_ != -1) {
              var strPos = document.frmMain.elements[i].id.indexOf("_");
              
var strId = document.frmMain.elements[i].id.slice(strPos + 1) + "_" + document.frmMain.elements[i].id.slice(0,strPos)               
     // this is the computation that I need to fixed the result into two decimal places
    document.frmMain.elements[i].value = document.getElementById(strId).value * document.getElementById('mult').value;  
     } 
    }  
}
</script>

Thank you so much

I am currently using a price calculator - although it's really not a calculator; I have to enter every price manually. Currently, it works in half inch increments.

I need it to do two things that it doesn't do currently:
1) Allow the customer to enter a dimension in 1/4 inch increments (1/8 would be even better, but I'm not requesting a miracle)
2) Make the result automatically round up to the nearest 1/2 inch

Page containing calculator

External file: sizecalc.js

To Forum

Thank you for being here. I have taken 2 calculators and edited them to get almost what i want. I need the final answer to round up to a whole number.

The page is
http://www.La-Dore.com/Goldleaf-Calculator.html

The code i think you want to see is ....

Code:

<!-- end of script 1 begining of 2-->
<SCRIPT LANGUAGE="JavaScript">
function perRound(num, precision) {

	var precision = 3; 
	precision = parseInt(precision); 

    var result1 = num * Math.pow(10, precision);

    var result2 = Math.round(result1);

    var result3 = result2 / Math.pow(10, precision);

    return zerosPad(result3, precision);

}



function zerosPad(rndVal, decPlaces) {

    var valStrg = rndVal.toString(); 
    var decLoc = valStrg.indexOf("."); 

    if (decLoc == -1) {

        decPartLen = 0; 
        valStrg += decPlaces > 0 ? "." : "";

    }

    else {

        decPartLen = valStrg.length - decLoc - 1; 
    }

     var totalPad = decPlaces - decPartLen;   

    if (totalPad > 0) {

      for (var cntrVal = 1; cntrVal <= totalPad; cntrVal++) 

            valStrg += "0";

        }

    return valStrg;

}


function clear_field(field) {

		if (field.value==field.defaultValue) {

			field.value=''

		}

	}
	



//Division

function doMath(form) {

var firstnumber = 0;

var secondnumber = 0;

var tempvalue = 0;

firstnumber = eval(form.firstnumber.value); //first number

secondnumber = eval(form.secondnumber.value); //second number

tempvalue = (firstnumber) / (secondnumber);

form.calcresult.value = (tempvalue); //out

}

//  -->

</script>

Wizards - I have a challenge!

I am writing a timecard app. The stipulatioin is all Hours fields can only be whole hours or half hour increments. For example, 1.0 is good, 1.5 is good, 1.2 is bad, 1.9 is bad.

I would like to have the field automatically change a value of 1.9 to a value of 2.0 (perhaps onKeyUp).

I would like to have the field automatically change a value of 3.2 to a value of 3.0.

In a nutshell - only allow whole and half hour values. Otherwise round up OR round down.

Thanks for any help you can provide. I am successfully using the Pengoworks plugin for calculations - absolutely priceless. If you think modifications can be made to it, plz let me know.

I have tried many ways to do this and have also searched the forum, no go. I was doing it manually doing this:

Code:

Math.round((#)*100)/100

But no go, so I found this function here on the forum:

Code:

function roundNumber(num, dec) {
	var result = Math.round(num*Math.pow(10,dec))/Math.pow(10,dec);
	return result;
}

No go, it works yes, don't get me wrong. But I am working on a invoicing system and it needs to be exact. For instance with this number:

Quote:
0.27470000001
It returns 0.27, when in reality it should return 0.28 because of the 7 changes the 4 to 5 and then 5 changes the 7 to 8. But it doesn't work.

While reading some things I found while searching google I see that Math.round doesn't work 100% the way it should mathematically.

So what options do I have left, I can't believe that a simple rounding calculationg that excel can do ha ha JS cannot.

Hi there,

To summarize my problem:
For example:
Sales : $ 5 (id=sales)
Discount: 11% (id=disc)
Total Discount: $ 0.55 (id=disc)
Rounded Discount: $ 0.6 (1 decimal) (id=rounded)
Net Sales: $ 4.40 (id=net_sales)

document.getElementById("net_sales").value = sales - rounded.toFixed(1);

Net Sales: $
<input id = "net_sales" type="Text" name="net_sales" size="4" value="<?php if (!empty($net_sales)) echo $net_sales; ?>">


I tried the above, it is working in the browser. However, it cannot be written into MYSQL (with PHP). What is wrong with my Javascript?

Thanks.