JavaScript实现表格行高亮变色

完整代码示例

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>表格动态变色</title>
    <style>
        th {
            background-color: pink;
        }
        
        .bg {
            background-color: green;
        }
    </style>
</head>

<body>
    <table border="1" cellpadding="8" cellspacing="0" align="center">
        <thead>
            <tr>
                <th>水果</th>
                <th>喜欢程度</th>
                <th>季节</th>
            </tr>
        </thead>
        <tbody>
            <tr>
                <td>苹果</td>
                <td>☆☆☆☆☆</td>
                <td>四季</td>
            </tr>
            <tr>
                <td>香蕉</td>
                <td>☆☆☆</td>
                <td>四季</td>
            </tr>
            <tr>
                <td>葡萄</td>
                <td>☆☆☆</td>
                <td>夏季</td>
            </tr>
            <tr>
                <td>榴莲</td>
                <td>☆☆☆☆☆☆☆</td>
                <td>夏季</td>
            </tr>
            <tr>
                <td>芒果</td>
                <td>☆☆☆☆☆☆☆</td>
                <td>夏季</td>
            </tr>
            <tr>
                <td>西瓜</td>
                <td>☆☆☆☆☆</td>
                <td>夏季</td>
            </tr>
        </tbody>
    </table>
    <script>
        var tr = document.querySelector('tbody').querySelectorAll('tr');
        for (var i = 0; i < tr.length; i++) {
            tr[i].onmouseover = function() {
                /* 排他算法
                for (var i = 0; i < tr.length; i++) {
                    tr[i].className = '';
                } */
                this.className = 'bg';
            }
            tr[i].onmouseout = function() {
                this.className = '';
            }
        }
    </script>
</body>

</html>