Javascript 稅收計算器輸入框不起作用

Question

這是一個家庭作業，我應該在其中編寫 JavaScript 函數（計算）以在點擊計算按鈕時計算和顯示銷售稅和總計。

這是為我提供的：

salesTax = 小計 * taxRate/100；

總計 = 小計 + 銷售稅；

和

必須是小於 10000000 的正數

必須是小於 50 的正數

這是我的代碼，你能告訴我為什么它不起作用嗎？ 我顯然是個新手：

<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>Sales Tax Calculator</title>
    <link rel="stylesheet" href="style.css" />
    <script>
        //function declaration for calculating sales tax
        function calculate() {
            //get three inputs from input boxes in the form
            let subtotal = parseInt(document.getElementById("subtotal").value);
            let taxRate = parseFloat(document.getElementById("tax_rate").value);

            //validation data
            if (subtotal <= 10000000 || tax_rate <= 50) {
                alert("sales tax exceeds 10000000 and/ or tax rate exceeds 50");
            } else {

                //calculate sales tax
                    salesTax = subtotal * taxRate / 100;
                    total = subtotal + salesTax;


                //display the results to the last two boxes
                document.getElementById("sales_tax").value = salesTax;
                document.getElementById("total").value = total;
            }
        }

        //function calling part

        //function named clear_form to clear every data entry in the clear_form
        //create function
        function clear_form() {
            document.getElementById("subtotal").value = " ";
            document.getElementById("tax_rate").value = " ";
            document.getElementById("sales_tax").value = " ";
            document.getElementById("total").value = " ";
            /*document.getElementById("investment").focus();*/
        }

        //function calling part using window.onload
        window.onload = function() {
            document.getElementById("calculate").onclick = calculate
            document.getElementById("clear").onclick = clear_form
        }
    </script>
</head>

<body>
    <div id="content">
        <h1>Sales Tax Calculator</h1>
        <p>Enter Subtotal and Tax Rate and click "Calculate".</p>
        <div id="taxCalc">
            <label for="subtotal">Subtotal:</label>
            <input type="text" id="subtotal">
            <span id="subtotal_message">Enter Order Subtotal</span><br />

            <label for="tax_rate">Tax Rate:</label>
            <input type="text" id="tax_rate">
            <span id="tax_rate_message">Enter Sales Tax Rate </span><br />

            <label for="sales_tax">Sales Tax:</label>
            <input type="text" id="sales_tax" disabled><br />

            <label for="total">Total:</label>
            <input type="text" id="total" disabled><br />

            <label>&nbsp;</label>
            <input type="button" id="calculate" value="Calculate">
            <input type="button" id="clear" value="Clear"><br />
        </div>
    </div>
</body>

</html>

Answer 1

我已經運行了您的代碼，但遇到了一個問題，使其無法運行：

            //validation data
if (subtotal <= 10000000 || tax_rate <= 50) {
alert("sales tax exceeds 10000000 and/ or tax rate exceeds 50");

你不小心混合了大於和小於符號！

它應該是：

//validation data
if (subtotal >= 10000000 || tax_rate >= 50) {
  alert("sales tax exceeds 10000000 and/ or tax rate exceeds 50");

試試這個，看看它是否有效。

Answer 2

你正在檢查錯誤的條件 -

if (subtotal <= 10000000 || tax_rate <= 50)

應該是以下條件——

if (subtotal >= 10000000 || tax_rate >= 50)

Javascript 稅收計算器輸入框不起作用

問題描述

2 個解決方案

解決方案1
0 2021-10-12 23:38:04

解決方案2
0 2021-10-12 23:38:41

Javascript 稅收計算器輸入框不起作用

問題描述

2 個解決方案

解決方案1 0 2021-10-12 23:38:04

解決方案2 0 2021-10-12 23:38:41

解決方案1
0 2021-10-12 23:38:04

解決方案2
0 2021-10-12 23:38:41