盈利？亏损？

衍生出来的想法……👉看这个页面

    <style>
        table {
            text-align: center;  /* 表格内容居中 */
        }
    </style>

    <div class="container">
        <table>
            <thead>
                <tr>
                    <th>设备编号</th>
                    <th>购买价格 (元)</th>
                    <th>购买时间</th>
                    <th>卖出时间</th>
                    <th>卖出价格 (元)</th>
                    <th>购买到卖出天数</th>
                    <th>每日均价 (元)</th>
                    <th>盈利/亏损 (元)</th>
                </tr>
            </thead>
            <tbody id="deviceTableBody">
                <!-- 初始设备记录（示例） -->
                <tr>
                    <td>1</td>
                    <td class="price">2000</td>
                    <td class="purchaseDate">2023-01-01</td>
                    <td class="sellDate">2024-01-01</td>
                    <td class="sellPrice">2500</td>
                    <td class="days">0</td>
                    <td class="averagePrice">0.00</td>
                    <td class="profitLoss">0.00</td>
                </tr>
                <tr>
                    <td>2</td>
                    <td class="price">1500</td>
                    <td class="purchaseDate">2022-11-01</td>
                    <td class="sellDate">2023-11-01</td>
                    <td class="sellPrice">1400</td>
                    <td class="days">0</td>
                    <td class="averagePrice">0.00</td>
                    <td class="profitLoss">0.00</td>
                </tr>
            </tbody>
        </table>

        <div class="result" id="result"></div>
    </div>

    <script>
        // 更新每一行的数据
        function updateRow(row) {
            var price = parseFloat(row.querySelector('.price').textContent);
            var sellPrice = parseFloat(row.querySelector('.sellPrice').textContent);
            var purchaseDate = new Date(row.querySelector('.purchaseDate').textContent);
            var sellDate = new Date(row.querySelector('.sellDate').textContent);

            // 检查数据是否有效
            if (isNaN(price) || isNaN(sellPrice) || isNaN(purchaseDate.getTime()) || isNaN(sellDate.getTime())) {
                return;  // 如果数据无效，不进行计算
            }

            // 计算从购买日期到卖出日期的天数
            var timeDifference = sellDate - purchaseDate;
            var days = Math.floor(timeDifference / (1000 * 60 * 60 * 24));  // 转换为天数

            // 更新购买到卖出天数
            row.querySelector('.days').textContent = days;

            // 如果天数为负，显示错误信息
            if (days <= 0) {
                row.querySelector('.averagePrice').textContent = "日期无效";
                row.querySelector('.profitLoss').textContent = "日期无效";
                return;
            }

            // 计算每日均价
            var averagePrice = (price / days).toFixed(2);

            // 更新每日均价
            row.querySelector('.averagePrice').textContent = averagePrice;

            // 计算盈利/亏损
            var profitLoss = (sellPrice - price).toFixed(2);

            // 判断盈利或亏损
            var profitLossText = profitLoss >= 0 ? `盈利 ${profitLoss}元` : `亏损 ${Math.abs(profitLoss)}元`;

            // 更新盈利/亏损
            row.querySelector('.profitLoss').textContent = profitLossText;
        }

        // 获取所有的设备行并进行计算
        function calculateAll() {
            var rows = document.querySelectorAll('#deviceTableBody tr');
            rows.forEach(function(row) {
                updateRow(row);
            });
        }

        // 初始化计算
        window.onload = function() {
            calculateAll();
        }
    </script>