For循环if语句在Javascript中识别==但不识别<

我试图创建一个脚本,用其他值替换表中的某些值。我用HTML生成了一个工作正常的表。我想用值1/8”替换前3行中第4列中的元素。

var rows = document.getElementsByTagName('tr');

for (var i = 0; i < rows.length; i++) {
 var cells = rows[i].getElementsByTagName('td');
 if (i < 3) {
  cells[3].innerHTML = '1/8"';
 }
}

使用上述代码对我的表没有任何作用,但是使用以下代码将第4个元素替换为我的值

var rows = document.getElementsByTagName('tr');

for (var i = 0; i < rows.length; i++) {
 var cells = rows[i].getElementsByTagName('td');
 if (i == 3) {
 cells[3].innerHTML = '1/8"';
 }
}

为什么==起作用,但<不是吗?有没有简单的方法可以打印出for循环的输出,这样我就可以更容易地调试-我对编码是新手。谢谢

编辑:这是我正在使用的HTML,以及CSS(可能不是必需的)

HTML5:

<div class="eo_product_listing_table">
<table class="tableizer-table">
<thead>
  <tr class="tableizer-firstrow">

    <th>Item #</th>
    <th>Type</th>
    <th>Operting Temp.</th>
    <th>O.D.</th>
    <th>Length</th>
    <th>Material</th>
    <th>Junction</th>
    <th>Price</th>
    <th>Order</th>
  </tr>
</thead>

<tbody>
  <!--1/8-->
  <!--6-->
  <tr>
    <td>NB4-CAXL-14U-12-AAG</td>
    <td>K</td>
    <td>-270°C to 1372°C</br>–454°F to 2501°F</td>
    <td>3/8"</td>
    <td>6"</td>
    <td>316SS</td>
    <td>Grounded</td>
    <td>$51.00</td>
    <td><a href="/">Order</a></td>
  </tr>
  <tr>
    <td>NB4-CAXL-14U-12-AAU</td>
    <td>K</td>
    <td>-270°C to 1372°C</br>–454°F to 2501°F</td>
    <td>3/8"</td>
    <td>6"</td>
    <td>316SS</td>
    <td>Ungrounded</td>
    <td>$53.00</td>
    <td><a href="/">Order</a></td>
  </tr>
  <tr>
    <td>NB4-CAXL-14U-12-AAE</td>
    <td>K</td>
    <td>-270°C to 1372°C</br>–454°F to 2501°F</td>
    <td>3/8"</td>
    <td>6"</td>
    <td>316SS</td>
    <td>Exposed</td>
    <td>$51.00</td>
    <td><a href="/">Order</a></td>
  </tr>
  <!--12-->
  <tr>
    <td>NB4-CAXL-14U-12-ABG</td>
    <td>K</td>
    <td>-270°C to 1372°C</br>–454°F to 2501°F</td>
    <td>3/8"</td>
    <td>12"</td>
    <td>316SS</td>
    <td>Grounded</td>
    <td>$53.00</td>
    <td><a href="/">Order</a></td>
  </tr>
  <tr>
    <td>NB4-CAXL-14U-12-ABU</td>
    <td>K</td>
    <td>-270°C to 1372°C</br>–454°F to 2501°F</td>
    <td>3/8"</td>
    <td>12"</td>
    <td>316SS</td>
    <td>Ungrounded</td>
    <td>$55.00</td>
    <td><a href="/">Order</a></td>
  </tr>
  <tr>
    <td>NB4-CAXL-14U-12-ABE</td>
    <td>K</td>
    <td>-270°C to 1372°C</br>–454°F to 2501°F</td>
    <td>3/8"</td>
    <td>12"</td>
    <td>316SS</td>
    <td>Exposed</td>
    <td>$53.00</td>
    <td><a href="/">Order</a></td>
  </tr>
  <!--18-->
  <tr>
    <td>NB4-CAXL-14U-12-ACG</td>
    <td>K</td>
    <td>-270°C to 1372°C</br>–454°F to 2501°F</td>
    <td>1/8"</td>
    <td>18"</td>
    <td>316SS</td>
    <td>Grounded</td>
    <td>$57.00</td>
    <td><a href="/">Order</a></td>
  </tr>
  <tr>
    <td>NB4-CAXL-14U-12-ACU</td>
    <td>K</td>
    <td>-270°C to 1372°C</br>–454°F to 2501°F</td>
    <td>1/8"</td>
    <td>18"</td>
    <td>316SS</td>
    <td>Ungrounded</td>
    <td>$59.00</td>
    <td><a href="/">Order</a></td>
  </tr>
  <tr>
    <td>NB4-CAXL-14U-12-ACE</td>
    <td>K</td>
    <td>-270°C to 1372°C</br>–454°F to 2501°F</td>
    <td>1/8"</td>
    <td>18"</td>
    <td>316SS</td>
    <td>Exposed</td>
    <td>$57.00</td>
    <td><a href="/">Order</a></td>
  </tr>
</tbody>

CSS3

.eo_product_listing_table {}

.tableizer-table tr:nth-child(even) {
   background-color: #eee;
}

table.tableizer-table {
  font-size: 12px;
  border: 1px solid #CCC;
  font-family: Arial, Helvetica, sans-serif;
  color: black;
}

.tableizer-table td {
  padding: 4px;
  margin: 3px;
  border: 0px solid #CCC;
  text-align: left;
  color: black;
}

.tableizer-table th {
  background-color: #104E8B;
  color: #FFF;
  font-weight: bold;
  text-align: left;
}

.tableizer-firstrow {
  background-color: #000;
  color: whtie;
}