javascript住宅ローン計算機

Question

私はこの住宅ローン計算機を構築することについて簡単に質問します。私はjavascriptには初心者ですが、他のプログラミング言語にはなじみがあります。 principal、termOfLoan、APRの値を入力してから計算ボタンを押すと、何も起こりません。誰かが簡単に私を逃しているものに導くことができますか？これは私が見落としている本当に迅速な解決策を持っているはずです。前もって感謝します。

<title>Mortgage Calculator</title> 
<meta charset = "UTF-8"> 
<link rel = "stylesheet" href = "mortgageCalculator.css"> 

<script> 

    function calculatePayment() { 


     var principal = parseFloat(document.getElementById("principal").value); 
     //principal = parseInt(principal); 

     var termOfLoan = parseFloat(document.getElementById("termOfLoan").value); 
     //termOfLoan = parseInt(termOfLoan); 

     var annualInterestRate = parseFloat(document.getElementById("annualInterestRate").value); 
     //annualInterestRate = parseFloat(annualInterestRate); 
     //document.getElementById("Calculate").value = principal * annualInterestRate/(1 -(Math.pow(1/(1 + annualInterestRate) , termOfLoan))); 
     //var monthlyPayment = principal * annualInterestRate/(1 -(Math.pow(1/(1 + annualInterestRate) , termOfLoan))); 

     var percentageRate = annualInterestRate/1200; 
     var lengthOfLoan = 12 * termOfLoan; 
     var monthlyPayment = (principal * percentageRate)/(1 - (Math.pow((1 + percentageRate) , lengthOfLoan * -1)))); 
     monthlyPayment = monthlyPayment.toFixed(2); 


     document.getElementById("payment").innerHTML = monthlyPayment; 

     //document.getElementById('monthlyPayment').innerHTML = "Monthly Payment" + monthlyPayment; 


    } 


</script> 

<h1>Mortgage Calculator</h1> 
<p>Use this simple home mortgage calculator to calculate monthly payments on mortgage rates. Payment examples shown do not include amounts for taxes and insurance premiums. 
*Note: please contact your financial insitution for final monthy payments, as the can and will vary from lender to lender. This calculator should only be used for comparison purposes</p> 
<form> 
<table> 

    <tr> 
     <td class = "labels">Principal Loan Amount</td> 
     <td class = "textbox"><input type = "text" id = "principal" onclick = "calculatePayment()"></td> 
    </tr> 
    <tr> 
     <td class = "labels">Mortgage Period (years)</td> 
     <td class = "textbox"><input type = "text" id = "termOfLoan" onclick = "calculatePayment()"></td> 
    </tr> 
    <tr> 
     <td class = "labels">Annual Interest Rate</td> 
     <td class = "textbox"><input type = "text" id = "annualInterestRate" onclick = "calculatePayment()"></td> 
    </tr> 
    <tr> 
     <td class = "labels">Monthly Mortgage Payment</td> 
     <td class = "textbox"><input type = "number" id = "payment" name = "monthlyPayment"></td> 

    </tr> 
    <tr> 
     <td class = "button"><button onclick = "calculatePayment()">Calculate</button></td> 
     <td class = "button"><input type = "reset" name = "Reset"></td> 
    </tr> 


</table> 
</form> 

Answer 1

あなたがvalueを使用する必要がありますので、お支払いはinputタグがあるhttps://jsfiddle.net/w4an90nr/

実施例ではないinnerHTML

document.getElementById("payment").value = monthlyPayment; //value not innerHTML 

もそれ

var monthlyPayment = (principal * percentageRate)/(1 - (Math.pow((1 + percentageRate) , lengthOfLoan * -1))); 

.removeここで追加の間違った閉じ括弧 )あり