Javascript in Mac: Number.toFixed challenge

Question posted by: glegipon (Newbie) on February 7th, 2006 10:19 AM

As Tom Cahill would require, my challenge is (according to the "three
R's")

Reproducible: if run on OS 9.x, the monthly payment does not show up in
the text box:

Recognizable: I believe the Mac OS 9.x is not getting the temp_var
value returned to the var MP to show in the form. My hypothesis is
that the problems lies in this function:

Expand|Select|Wrap|Line Numbers

	     function round_2(Number) 

    {

    var temp_var = (Number.toFixed(2))

    return temp_var

    }

Repairable:I believe I've located the error location, but this is my
2nd day coding Javascript, so I don't know if it's repairable. Is
there a fix to this? I heard if the Number.toFixed method isn't
available on the operating system, it is possible to write that method
as a function.

Here's my code:

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<HTML><HEAD><TITLE>Simple Mortgage Calculator</TITLE>

<script language="JavaScript"> 

function round_2(Number)

{

var temp_var = (Number.toFixed(2))

return temp_var

}
 
function find_payment(A, B, C)

{

var temp_var = (A * B) / (1 - Math.pow(1 + B, -C))

return temp_var

}
 
function dosum()

{

if(document.temps.PP.value>0)

{

if((document.temps.DP.value / document.temps.PP.value) <=0)

{document.temps.DP.value=document.temps.PP.value/10}

else if((document.temps.DP.value/document.temps.PP.value)<.1)

{

alert("A 10% Miminimum Down Payment Is Required.")

document.temps.DP.value=document.temps.PP.value/10

}

else if((document.temps.DP.value/document.temps.PP.value)>=1)

{

alert("Come on. If you pay for the property in full at time of

purchase, you won't need a loan. Why are you looking at terms? If you

are going to pay in full, call me at (800) 760-3001 and I'll give you a

5% discount on the purchase of any property on our inventory.")

document.temps.DP.value=document.temps.PP.value/10

}

else

{document.temps.DP.value=document.temps.DP.value}
 
if(document.temps.YR.value<=0)

{document.temps.YR.value=15}

else if(document.temps.YR.value>30)

{

alert("30 Year Is The Maximum Repayment Period.")

document.temps.YR.value=30

}

else

{document.temps.YR.value=document.temps.YR.value}
 
document.temps.LA.value=document.temps.PP.value-document.temps.DP.value

if((document.temps.DP.value/document.temps.PP.value)<.2)

{document.temps.IR.value=.09}

else if((document.temps.DP.value/document.temps.PP.value)<.3)

{document.temps.IR.value=.085}

else

{document.temps.IR.value=.08}

var MP = document.temps.MP.value

var LA = document.temps.LA.value

var IR = document.temps.IR.value

var YR = document.temps.YR.value

MP=find_payment(LA,IR/12,YR*12)
 
document.temps.AT.value=(document.temps.PP.value*.  0125)
 
document.temps.MP.value=round_2(MP)

}

else

{alert("Please Enter A Purchase Price")}

}

function clearboxes()

{

document.temps.PP.value = "";

document.temps.DP.value = "";

document.temps.LA.value = "";

document.temps.YR.value = "";

document.temps.IR.value = "";

document.temps.MP.value = "";

document.temps.AT.value = "";

}

// -->

</script>

</HEAD><b>Simple Mortgage Calculator</b><br>

<br>

<form name="temps">

Loan Details...<br><br>

<u>variable price</u>

<br>Purchase Price:<input NAME="PP" onfiltered="dosum()" tabindex="1"

size=15 style="font-size:9pt;">

<hr width=95%><br><br>

<u>terms are flexible</u>

<br>Down Payment:<input NAME="DP" onfiltered="dosum()" tabindex="1"

size=15 style="font-size:9pt;">

<br>Repayment Period: (Years)<input NAME="YR" onfiltered="dosum()"

tabindex="2" size=15 style="font-size:9pt;">

<br>

<br>

Results...<br><br>

<u>fixed numbers</u>

<br>Monthly Payment:<input size=13 NAME="MP" style="font-size:9pt;"

tabindex="8">

<br>Loan Amount:<input NAME="LA" onfiltered="dosum()" tabindex="1"

size=15 style="font-size:9pt;">

<br>Interest Rate:<input size=15 style="font-size:9pt;" NAME="IR"

"onfiltered="dosum()" tabindex="3">

<br>Annual County Tax:<input size=13 NAME="AT" style="font-size:9pt;"

tabindex="11">

<br>
 
<br><br><blockquote><a href="javascript:clearboxes()" width=58

height=16 border=0>Clear</a>

<br><br><a href="javascript:dosum()" width=100 height=16

border=0>CALCULATE</a>

</blockquote>

<div align=center><font size=1>Calculations made by this tool are

believed to be accurate but are not guaranteed.</font></div>

</BODY></HTML>

Thanks for your help

acoder

Site Moderator

11,540 Posts

April 16th, 2008
11:18 AM
#2

Re: Javascript in Mac: Number.toFixed challenge

You can add toFixed if it doesn't exist. Either use a function or add it directly using prototype, e.g.

Expand|Select|Wrap|Line Numbers

	if (!num.toFixed) {

    Number.prototype.toFixed = function(precision) {

        var num = (Math.round(this*Math.pow(10,precision))).toString  ();

        return num.substring(0,num.length-precision) + "." + num.substring(num.length-precision, num.length);

    }

}

gits

Moderator

3,202 Posts

April 16th, 2008
12:01 PM
#3

Re: Javascript in Mac: Number.toFixed challenge

and one more thing to mention: the problem is not the MAC ... it is the browser you would use with it that has to have an implementation of ECMA-Script ... and so the problem is the browser that is used with a specific OS ... and from that point of view the OS could be a problem when it limits the use of an up to date browser or the user who wants to use a specific browser that you have to support - but not the MAC itself :) ...

just this two cents from a MAC-user ... :)

kind regards

acoder

Site Moderator

11,540 Posts

April 16th, 2008
12:57 PM
#4

Re: Javascript in Mac: Number.toFixed challenge

Yes, of course, you're absolutely right!

Forgot to mention that... thanks!

It's probably either IE5 on the Mac or an old version of Safari that's the problem.

mrhoo

Needs Regular Fix

408 Posts

April 16th, 2008
01:52 PM
#5

Re: Javascript in Mac: Number.toFixed challenge

While acoder's method is flawless, and gits remarks apt, I am not sure that toFixed is the problem. I didn't remember the 'onfilter ' event, which is the one calling the method, untitl I googled it,

Quote:

onfilter is a non existent event handler that web based email services such as Yahoo mail uses in place of actual event handlers inside emails that contain a JavaScript. It's a security precaution, to disable any malicious script from executing in the user's browser.

This doesn't mean he has the method toFixed, and anyone who doesn't can use acoder's replacement, but what event calls dosum?

acoder

Site Moderator

11,540 Posts

April 17th, 2008
09:09 AM
#6

Re: Javascript in Mac: Number.toFixed challenge

Good spot! Goes to show that three (sets of) eyes are better than one...

Quote:

what event calls dosum?

Probably via the CALCULATE link at the bottom, though onfiltered should probably be onchange.

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