【发布时间】：2014-06-29 19:46:18
【问题描述】：
在过去的几天里，我一直在发疯，试图弄清楚这一点，我完全不知道该怎么办。
对于我必须为课堂做的作业，我们必须分析以下 JavaScript 代码并纠正错误。我已经设法弄清楚其中的大部分内容，但我被困在最后一部分。
每当我单击“计算”按钮时，它都会返回 "$NaN.undefined" 以获取每月付款金额。我一遍又一遍地查看代码，一切似乎都与我教科书中显示的内容相匹配，所以我不知道我需要更改什么才能使其正常工作。
几天前我刚开始学习 JavaScript，所以我在这方面还很陌生。任何人都可以给我的任何帮助或指导将不胜感激。
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-type" content="text/html;charset=UTF-8" />
<title>Make10-1 Oakwood Mortgage</title>
<script type="text/javascript">
<!--Hide from old browsers
var thisMsg=" ** See us for your auto loan financing needs!!! ** "
var beginPos=0
function scrollingMsg() {
msgForm.scrollingMsg.value=thisMsg.substring(beginPos,thisMsg.length)+thisMsg.substring(0,beginPos)
beginPos+=1
if (beginPos > thisMsg.length) {
beginPos=0
}
window.setTimeout("scrollingMsg()",200)
}
var salesAmt
var loanAmt
var loanRate
var loanYears
function valSaleDownAmt() {
var salesAmt=parseInt(LoanCalc.SaleAmt.value,10)
if (isNaN(salesAmt) || (salesAmt <=0)) {
alert("The sales amount is not a valid number!")
LoanCalc.SaleAmt.value = ""
LoanCalc.SaleAmt.focus()
}
else {
var DownPayment=parseFloat(LoanCalc.DownPmt.value)/100
if (isNaN(DownPayment) || (DownPayment <= 0) || DownPayment > 100) {
alert("The Down Payment Rate is not a valid number!")
LoanCalc.DownPmt.value = " "
LoanCalc.DownPmt.focus()
}
else {
var amtDown = salesAmt*DownPayment
var loanAmt = salesAmt-amtDown
LoanCalc.LoanAmt.value = dollarFormat(loanAmt.toFixed(2))
LoanCalc.Rate.focus()
}
}
}
function CalcLoanAmt() {
loanRate=parseFloat(LoanCalc.Rate.value)
if (isNaN(loanRate) || (loanRate <= 0)) {
alert("The interest rate is not a valid number!")
LoanCalc.Rate.value = ""
LoanCalc.Rate.focus()
}
else {
loanYears=parseInt(LoanCalc.Years.selectedIndex)
if (isNaN(loanYears) || (loanYears < 1)) {
alert("Please select a valid number of years from the list!")
LoanCalc.Years.selectedIndex = "0"
LoanCalc.Years.focus()
}
else {
var monthlyPmt = monthly(loanAmt,loanRate,loanYears)
LoanCalc.Payment.value=dollarFormat(monthlyPmt.toString())
}
}
}
function monthly(loanAmt,loanRate,loanYears) {
var Irate = loanRate/1200
var Pmts = loanYears*12
var Amnt = loanAmt * (Irate / (1 - (1 / Math.pow(1+Irate,Pmts))))
return Amnt.toFixed(2)
}
function dollarFormat(valuein) {
var formatValue = ""
var formatDollars = ""
formatAmt = valuein.split(".",2)
var dollars = formatAmt[0]
var dollarLen = dollars.length
if (dollarLen > 3) {
while (dollarLen > 0) {
tempDollars = dollars.substring(dollarLen - 3,dollarLen)
if (tempDollars.length == 3) {
formatDollars = "," + tempDollars + formatDollars
dollarLen = dollarLen - 3
} else {
formatDollars = tempDollars + formatDollars
dollarLen = 0
}
}
if (formatDollars.substring(0,1) == ",")
dollars = formatDollars.substring(1,formatDollars.length)
else
dollars = formatDollars
}
var cents = formatAmt[1]
var formatValue="$"+dollars+"."+cents
return formatValue
}
function popUpAd() {
open("make10-1notice.html","noticeWin","width=520,height=270")
}
function lastModified() {
var lastModDate = document.lastModified
var lastModDate = lastModDate.substring(0,10)
displayDateLast.innerHTML="<span style='font-family:Arial, Helvetica, sans-serif; font-size:9px; font-weight:bold'>This document was last modified "+lastModDate+"</span>"
}
//-->
</script>
<style type="text/css">
<!--
body {
background-image: url(financial_symbol.jpg);
}
-->
</style>
</head>
<body onload="scrollingMsg(); popUpAd(); lastModified()">
<div align="center">
<p align="center"><img src="make10-1banner.jpg" width="750" height="120" alt="banner" /></p>
<form id="msgForm" action="">
<p style="text-align:center"><input type="text" name="scrollingMsg" size="25" /></p>
</form>
</div>
<div style="font-family:Arial, Helvetica, sans-serif">
<h3 align="center">Home Loan Payment Calculator</h3>
<form id="LoanCalc" action="">
<table width="346" align="center" cellspacing="3">
<tr>
<td align="right">
<span style="color:#cc0000">*</span>Sale Price:
</td>
<td><input type="text" name="SaleAmt" id="SaleAmt" size="9" /></td>
</tr>
<tr>
<td align="right">
<span style="color:#cc0000">*</span> Down Payment as a percent
</td>
<td><input name="DownPmt" type="text" id="DownPmt" size="4" onblur="valSaleDownAmt()" />
%</td>
</tr>
<tr>
<td align="right">
<span style="color:#cc0000">*</span> Interest Rate (e.g. 5.9):
</td>
<td><input type="text" name="Rate" id="Rate" size="4" /> %
</td>
</tr>
<tr>
<td align="right">
<span style="color:#cc0000">*</span> Select Number of Years:
</td>
<td><select name="Years" id="Years">
<option selected="selected">Select Years</option>
<option value="10">10</option>
<option value="15">15</option>
<option value="20">20</option>
<option value="25">25</option>
<option value="30">30</option>
<option value="40">40</option>
</select></td>
</tr>
<tr>
<td align="right">
<input name="button" type="button" value="Calculate" onclick="CalcLoanAmt()" />
</td>
<td>
<input name="Reset" type="reset" />
</td>
</tr>
<tr>
<td align="right">
<span style="color:#cc0000">*</span> Loan Amount
</td>
<td>
<input name="LoanAmt" type="text" id="LoanAmt" size="9" />
</td>
</tr>
<tr>
<td align="right">
<span style="font-weight:bolder">Monthly Payment</span>:
</td>
<td><input type="text" name="Payment" id="Payment" value=" " size="12" /></td>
</tr>
</table>
<p style="color:#cc0000; text-align:center">* Indicates a required field.</p>
</form>
</div>
<div id="displayDateLast" style="margin-left:5%">
</div>
</body>
</html>
【问题讨论】：
-
@adeneo：或者她决定享受漂亮、干净、无分号的代码。
-
@cookiemonster - 废话，我什至没有考虑过，但可能就是这样。它们看起来确实很丑，我们真的不需要它们
-
@adeneo：我相信我提到这不是我的代码，这是提供给我的代码，我必须检查错误。没有分号不是我的决定。
标签： javascript