javascript loop payment code example
Example: javascript loop payment
<html>
<head>
<title></title>
<script type="text/javascript">
function fixVal(value,numberOfCharacters,numberOfDecimals,padCharacter) {
var i, stringObject, stringLength, numberToPad;
value = value * Math.pow(10,numberOfDecimals);
value = Math.round(value);
stringObject = new String(value);
stringLength = stringObject.length;
while(stringLength < numberOfDecimals) {
stringObject = "0"+stringObject;
stringLength=stringLength+1;
}
if(numberOfDecimals>0) {
stringObject=stringObject.substring(0,stringLength-numberOfDecimals)+"."+
stringObject.substring(stringLength-numberOfDecimals,stringLength);
}
if (stringObject.length<numberOfCharacters && numberOfCharacters>0) {
numberToPad=numberOfCharacters-stringObject.length;
for (i=0; i<numberToPad; i=i+1) {
stringObject=padCharacter+stringObject;
}
}
return stringObject;
}
function buildTable() {
var amount=parseFloat(document.getElementById("loanAmt").value );
var numpay=parseInt(document.getElementById("monthlyPay").value );
var rate=parseFloat(document.getElementById("intRte").value );
rate = rate / 100;
var monthly = rate / 12;
var payment = ((amount * monthly) / (1-Math.pow((1 + monthly), - numpay)));
var total = payment * numpay;
var interest = total - amount;
var msg = "<table border='4' width='75%'>";
msg += "<tr>";
msg += "<td>Month</td>";
msg += "<td>Principal Paid</td>";
msg += "<td>Interest Paid</td>";
msg += "<td>Loan Balance</td>";
msg += "</tr>";
newPrincipal=amount;
var i = 1;
while (i <= numpay) {
newInterest=monthly*newPrincipal;
reduction=payment-newInterest;
newPrincipal=newPrincipal-reduction;
msg += "<tr><td align='left' bgcolor='pink'>"+i+"</td> \
<td align='left' bgcolor='pink'>"+fixVal(reduction,0,2,' ')+"</td> \
<td align='left' bgcolor='pink'>"+fixVal(newInterest,0,2,' ')+"</td> \
<td align='left' bgcolor='pink'>"+fixVal(newPrincipal,0,2,' ')+"</td></tr>";
i++;
}
msg += "</table>";
document.getElementById("results").innerHTML = msg;
}
</script>
<style type="text/css">
body {
background: black;
font-family: arial;
}
#contentwrap {
width: 700px;
margin: 40px auto 0px auto;
background: #FFFFCC;
text-align: center;
border: 6px red solid;
border-radius: 10px;
padding: 40px;
}
table {
border: 5px blue double;
background-color: #FFFFCC;
}
#header {
text-align: center;
font-size: 2.5em;
text-shadow: yellow 3px 3px;
margin-bottom: 18px;
color: red;
}
#button {
background: blue;
color: white;
cursor: pointer;
padding: 5px 0px 5px 0px;
border: 1px solid red;
border-radius: 25px;
width: 150px;
}
.contentTitles {
color: green;
font-weight: bold;
}
.style {
background: lightblue;
font-family: comic sans ms;
border: 6px blue double;
color: green;
font-weight: bold;
}
</style>
</head>
<body>
<div id="contentwrap">
<div id="header">Javascript Loan Calculator</div>
<form>
<div class="contentTitles">Enter Loan Amount<br />
<input type="text" id="loanAmt" class="style"><p />
Interest Rate (%)<br />
<input type="text" id="intRte" class="style"><p />
Monthly Payment Amount<br />
<input type="text" id="monthlyPay" class="style"><p />
<div style="margin-top:20px;">
<input type="button" value="Process Data" id="button" onClick="buildTable()">
</div>
</form>
<center>
<div id="results" style="margin-top:20px;"></div>
</center>
</div> <!-- ends div#contentwrap -->
</body>
</html>