Question

我有一个包含6行和x列的表。我需要将单元格的背景颜色更改为包含在数组中的颜色。颜色索引匹配应绘制的行数。我有下一组颜色：

var arr = ["lightgreen", "orange", "red"];

我的jQuery脚本：

$.each(arr, function(index, val) {
$("tr:eq(" + (index) + ")").css("background-color", val);
});

这段代码只绘制不同颜色的前三行。我需要这样的输出表：

lightgreen lightgreen lightgreen lightgreen
orange orange orange orange
orange orange orange orange
red red red red
red red red red
red red red red

我的jsfiddle：http://jsfiddle.net/kvdokq13/

Answer 1

您希望每次都处理 N行，而使用$("tr:eq(" + (index) + ")")仅选择唯一的第N 行！

你可以这样做：

var arr = ["lightgreen", "orange", "red"];
var $rows = $('tr');
var nextRow = 0;
$.each(arr, function(index, val) {
    for (var i = 0; i < index + 1; i++) {
    $rows.eq(nextRow++).css("background-color", val);
  }
});

http://jsfiddle.net/kvdokq13/6/

为了更广泛的使用，请注意应该增强这一点以正确处理数组长度和行数之间的差异：目前它假定有(1 + 2 + ... + N)行！

Answer 2

修改了Azim的asnwer ......

var arr = ["lightgreen", "orange", "red"];
var tr = $('table tr');

for (var i=0; i<tr.length; i++){
  $(tr[i]).css("background-color", arr[i]);
   if (i>2){
        $(tr[i]).css("background-color", arr[2]);
  }    
}

http://jsfiddle.net/kvdokq13/5/

这可能只使用css更有效但我猜JQuery是必须的吗？

Answer 3

您应该保留数字需要跳过多少行：

var arr = ["lightgreen", "orange", "red"];
var skip = 0;
$.each(arr, function(index, val) {
    var _repeat = index+1; // js arrays are zero indexed
    for (var i = 0; i < _repeat; i++) 
        $("tr:eq(" + (i+skip) + ")").css("background-color", val);
  skip = skip + _repeat;
});

updated fiddle

Answer 4

虽然你已经接受了这个问题的答案，但我认为我会使用普通的JavaScript而不是库来提供替代方案，以防万一可能有用。

请注意，我使用了一些ECMAScript 6功能，“胖箭头”语法和Array.from()（请参阅下面的参考资料），不过我会发布一个替代方案（在我的答案的“主要”部分下方）如果您还不想使用ES6，则显示另一种实现方式。

那就是说，我自己的解决方案是：

// the colors Array:
var colors = ["lightgreen", "orange", "red"],
// a reference to the <table> element that is
// to be coloured:
  table = document.querySelector('table');

// declaring the relevant function to handle the 
// colouring:
function colorNRows(arr, table) {

  // caching the rows of the table:
  var rows = table.rows,

  // using Array.from() to convert the HTMLCollection
  // into an Array:
    clone = Array.from(rows),

  // iterating over the array of colours, using
  // Array.prototype.map(),
  // row:   the array-element of the array over which
  //        we're iterating,
  // index: the index of the current array-element
  //        in that array,
  // array: (unused here), the array over which we're
  //        iterating.
    segments = arr.map(function(row, index, array) {

      // removing 'index+1' elements of the array from
      // the clone Array, starting at index 0 and
      // returning the removed row(s) to form a new
      // Array:
      return clone.splice(0, index + 1);

    // iterating over the newly-formed Array,
    // using Array.prototype.forEach();
    // the automagically-passed array-elements
    // are, as above, the array-element (of the new
    // array) and the index of the current
    // array-element (in that array):
    }).forEach(function(rowSegments, index) {

      // here we iterate over the array(s) held
      // in each array-element, again using the
      // automagic variables are the same as above
      // relative to the current array.

      // we're using the 'fat arrow' syntax to pass
      // the array-element (toColor) into the
      // the process on the right hand side, thereby
      // styling the backgroundColor of each array-element
      // (a <tr>) according to the color held in the 'arr'
      // array, at the index held in the outer forEach():
      rowSegments.forEach(toColor => toColor.style.backgroundColor = arr[index]);
    });
}

// calling the function:
colorNRows(colors, table);

var colors = ["lightgreen", "orange", "red"],
  table = document.querySelector('table');

function colorNRows(arr, table) {
  var rows = table.rows,
    clone = Array.from(rows),
    segments = arr.map(function(row, index, array) {
      return clone.splice(0, index + 1);
    }).forEach(function(rowSegments, index) {
      rowSegments.forEach(toColor => toColor.style.backgroundColor = arr[index]);
    });
}

colorNRows(colors, table);

<table border="4" cellpadding="4" cellspacing="4">
  <tr>
    <td>1</td>
    <td>2</td>
    <td>3</td>
    <td>4</td>
    <td>5</td>
    <td>6</td>
    <td>7</td>
    <td>8</td>
    <td>9</td>
    <td>10</td>
  </tr>
  <tr>
    <td>11</td>
    <td>12</td>
    <td>13</td>
    <td>14</td>
    <td>15</td>
    <td>16</td>
    <td>17</td>
    <td>18</td>
    <td>19</td>
    <td>20</td>
  </tr>
  <tr>
    <td>21</td>
    <td>22</td>
    <td>23</td>
    <td>24</td>
    <td>25</td>
    <td>26</td>
    <td>27</td>
    <td>28</td>
    <td>29</td>
    <td>30</td>
  </tr>
  <tr>
    <td>31</td>
    <td>32</td>
    <td>33</td>
    <td>34</td>
    <td>35</td>
    <td>36</td>
    <td>37</td>
    <td>38</td>
    <td>39</td>
    <td>40</td>
  </tr>
  <tr>
    <td>41</td>
    <td>42</td>
    <td>43</td>
    <td>44</td>
    <td>45</td>
    <td>46</td>
    <td>47</td>
    <td>48</td>
    <td>49</td>
    <td>50</td>
  </tr>
  <tr>
    <td>51</td>
    <td>52</td>
    <td>53</td>
    <td>54</td>
    <td>55</td>
    <td>56</td>
    <td>57</td>
    <td>58</td>
    <td>59</td>
    <td>60</td>
  </tr>
</table>

JS Fiddle demo

删除ES6功能，与大多数现代浏览器兼容，让我们留下以下内容（除了注释代码之外的所有内容都完全相同）：

function colorNRows(arr, table) {
  var rows = table.rows,

  // cloning the rows HTMLCollection, using
  // Array.prototype.slice() in conjunction with
  // Function.prototype.call(), to allow us to use
  // slice() on the Array-like collection:
    clone = Array.prototype.slice.call(rows, 0),

    segments = arr.map(function(row, index, array) {
      return clone.splice(0, index + 1);
    }).forEach(function(rowSegments, index) {

      // here, rather than a fat arrow function,
      // we explicitly use an inner forEach() loop
      // performing the same action, but slightly
      // more verbose:
      rowSegments.forEach(function(toColor) {
        toColor.style.backgroundColor = arr[index];
      })
    });
}

var colors = ["lightgreen", "orange", "red"],
  table = document.querySelector('table');

function colorNRows(arr, table) {
  var rows = table.rows,
    clone = Array.prototype.slice.call(rows, 0),
    segments = arr.map(function(row, index, array) {
      return clone.splice(0, index + 1);
    }).forEach(function(rowSegments, index) {
      rowSegments.forEach(function(toColor) {
        toColor.style.backgroundColor = arr[index];
      })
    });
}

colorNRows(colors, table);

<table border="4" cellpadding="4" cellspacing="4">
  <tr>
    <td>1</td>
    <td>2</td>
    <td>3</td>
    <td>4</td>
    <td>5</td>
    <td>6</td>
    <td>7</td>
    <td>8</td>
    <td>9</td>
    <td>10</td>
  </tr>
  <tr>
    <td>11</td>
    <td>12</td>
    <td>13</td>
    <td>14</td>
    <td>15</td>
    <td>16</td>
    <td>17</td>
    <td>18</td>
    <td>19</td>
    <td>20</td>
  </tr>
  <tr>
    <td>21</td>
    <td>22</td>
    <td>23</td>
    <td>24</td>
    <td>25</td>
    <td>26</td>
    <td>27</td>
    <td>28</td>
    <td>29</td>
    <td>30</td>
  </tr>
  <tr>
    <td>31</td>
    <td>32</td>
    <td>33</td>
    <td>34</td>
    <td>35</td>
    <td>36</td>
    <td>37</td>
    <td>38</td>
    <td>39</td>
    <td>40</td>
  </tr>
  <tr>
    <td>41</td>
    <td>42</td>
    <td>43</td>
    <td>44</td>
    <td>45</td>
    <td>46</td>
    <td>47</td>
    <td>48</td>
    <td>49</td>
    <td>50</td>
  </tr>
  <tr>
    <td>51</td>
    <td>52</td>
    <td>53</td>
    <td>54</td>
    <td>55</td>
    <td>56</td>
    <td>57</td>
    <td>58</td>
    <td>59</td>
    <td>60</td>
  </tr>
</table>

JS Fiddle demo

参考文献：

使用jQuery更改表格单元格的背景颜色

4 个答案: