如何同时为多个元素应用悬停事件？

Question

我对 JavaScript 非常陌生，希望为每一行分组表数据。 每行有6个表数据。 我希望前 3 个链接在一起，后 3 个分开。 为我想要链接在一起的列创建一个 className 会使所有表悬停。 我只希望特定的行值可以悬停。

var table = document.getElementsByTagName("tbody");

for (var i = 0; i < table.length-1; i++){

    var currentTable = table[i];
    var rows = currentTable.getElementsByTagName("tr");

    for(var j = 3; j < rows.length-1; j++){

        var c = rows[j].cells;

        c[0].className = "fall";
        c[1].className = "fall";
        c[2].className = "fall";
        // for each row make these three selectable

        c[3].className = "spring";
        c[4].className = "spring";
        c[5].className = "spring";
    }
}

除了为每一行创建一个新的类名之外，我不确定是否有更好的方法来做到这一点。 如果我需要这样做，有没有一种简单的方法可以动态地做到这一点？ 如果您想查看实际表，请告诉我。 谢谢你。

Answer 1

当然，您可以使用 CSS 通过基于索引对它们进行分类来做到这一点：

 td:nth-child(1), td:nth-child(2), td:nth-child(3) { color: red; } td:nth-child(4), td:nth-child(5), td:nth-child(6) { color: green; }

 <table> <tbody> <tr> <td>Cell 1</td> <td>Cell 2</td> <td>Cell 3</td> <td>Cell 4</td> <td>Cell 5</td> <td>Cell 6</td> </tr> <tr> <td>Cell 7</td> <td>Cell 8</td> <td>Cell 9</td> <td>Cell 10</td> <td>Cell 11</td> <td>Cell 12</td> </tr> </tbody> </table>

参考： :nth-child()

---

更新：

 $('td:nth-child(1),td:nth-child(2),td:nth-child(3)').on('mouseover', function () { var index = $(this).index() + 1; $('table td:nth-child(' + index + ')').css('color', 'red'); }); $('td:nth-child(1),td:nth-child(2),td:nth-child(3)').on('mouseout', function () { var index = $(this).index() + 1; $('table td:nth-child(' + index + ')').css('color', 'black'); }); $('td:nth-child(4),td:nth-child(5),td:nth-child(6)').on('mouseover', function () { var index = $(this).index() + 1; $('table td:nth-child(' + index + ')').css('color', 'green'); }); $('td:nth-child(4),td:nth-child(5),td:nth-child(6)').on('mouseout', function () { var index = $(this).index() + 1; $('table td:nth-child(' + index + ')').css('color', 'black'); });

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <h3>Table 1</h3> <table> <tbody> <tr> <td>Cell 1</td> <td>Cell 2</td> <td>Cell 3</td> <td>Cell 4</td> <td>Cell 5</td> <td>Cell 6</td> </tr> </tbody> </table> <h3>Table 2</h3> <table> <tbody> <tr> <td>Cell 7</td> <td>Cell 8</td> <td>Cell 9</td> <td>Cell 10</td> <td>Cell 11</td> <td>Cell 12</td> </tr> </tbody> </table>

---

更新 2：

 $('td:nth-child(1),td:nth-child(2),td:nth-child(3)').on('mouseover', function () { $('td:nth-child(1),td:nth-child(2),td:nth-child(3)').css('color', 'red'); }); $('td:nth-child(1),td:nth-child(2),td:nth-child(3)').on('mouseout', function () { $('td:nth-child(1),td:nth-child(2),td:nth-child(3)').css('color', 'black'); }); $('td:nth-child(4),td:nth-child(5),td:nth-child(6)').on('mouseover', function () { $('td:nth-child(4),td:nth-child(5),td:nth-child(6)').css('color', 'green'); }); $('td:nth-child(4),td:nth-child(5),td:nth-child(6)').on('mouseout', function () { $('td:nth-child(4),td:nth-child(5),td:nth-child(6)').css('color', 'black'); });

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <h3>Table 1</h3> <table> <tbody> <tr> <td>Cell 1</td> <td>Cell 2</td> <td>Cell 3</td> <td>Cell 4</td> <td>Cell 5</td> <td>Cell 6</td> </tr> </tbody> </table> <h3>Table 2</h3> <table> <tbody> <tr> <td>Cell 7</td> <td>Cell 8</td> <td>Cell 9</td> <td>Cell 10</td> <td>Cell 11</td> <td>Cell 12</td> </tr> </tbody> </table>

或者，如果您只想在 1 行上使用该事件，则可以将该事件编辑为：

$('td:nth-child(1),td:nth-child(2),td:nth-child(3)').on('mouseover', function () {

  $(this).parent().find('td:nth-child(1),td:nth-child(2),td:nth-child(3)').css('color', 'red');

});

---

更新 3：

 $('td').on('mouseover', function () { var tr = $(this).parent(); var index = $(this).index(); var cells = index < 3 ? [1, 2, 3] : [4, 5, 6]; var color = index < 3 ? 'red' : 'green'; cells.forEach(function (x) { tr.find('td:nth-child(' + x + ')').css('color', color); }); }); $('td').on('mouseout', function () { $(this).parent().find('td').css('color', 'black'); });

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <h3>Table 1</h3> <table> <thead> <tr> <th>H1</th> <th>H2</th> <th>H3</th> <th>H4</th> <th>H5</th> <th>H6</th> </tr> </thead> <tbody> <tr> <td>Cell 1</td> <td>Cell 2</td> <td>Cell 3</td> <td>Cell 4</td> <td>Cell 5</td> <td>Cell 6</td> </tr> </tbody> </table> <h3>Table 2</h3> <table> <thead> <tr> <th>H1</th> <th>H2</th> <th>H3</th> <th>H4</th> <th>H5</th> <th>H6</th> </tr> </thead> <tbody> <tr> <td>Cell 7</td> <td>Cell 8</td> <td>Cell 9</td> <td>Cell 10</td> <td>Cell 11</td> <td>Cell 12</td> </tr> </tbody> </table>