如何使用jQuery过滤器选择器查找表标记td值

Question

<table>
    <tr>
        <td>Calories </td>
        <td>TargetValue1</td>
    </tr>
    <tr>
        <td>Protein</td>
        <td>TargetValue2</td>
    </tr> 
    <tr>
        <td>Protein</td>
        <td>TargetValue3</td>
    </tr> 

如何选择所有第二个td 值？

我试过

    $.each($("#nutritab tbody tr td:eq(1)"),function(i , item){
        alert($(item).text());  
    });

但只返回第一个值。

Answer 1

  

使用nth-child选择器代替:eq(index)

:nth-child(n)选择器匹配每个元素，即nth child()（Index starts from 1）

:eq(index)选择器会在匹配集中的索引n处选择元素。（Zero-based index）

$.each($("#nutritab tr td:nth-child(2)"), function(i, item) {
  alert($(item).text());
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<table id='nutritab'>
  <tr>
    <td>Calories</td>
    <td>TargetValue1</td>
  </tr>
  <tr>
    <td>Protein</td>
    <td>TargetValue2</td>
  </tr>
  <tr>
    <td>Protein</td>
    <td>TargetValue3</td>
  </tr>
</table>

Answer 2

＆＃13;

＆＃13;

$.each($("#nutritab tbody tr"), function(i, item) {
  alert($(this).find('td:nth-child(2)').text());
});

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table id='nutritab'>
  <tr>
    <td>Calories</td>
    <td>TargetValue1</td>
  </tr>
  <tr>
    <td>Protein</td>
    <td>TargetValue2</td>
  </tr>
  <tr>
    <td>Protein</td>
    <td>TargetValue3</td>
  </tr>

＆＃13;

＆＃13;

＆＃13;

1. 首先将id命名为表
2. 使用。nth-child() 注意：从1
开始

Answer 3

您可以使用nth child() of selector选择器，它匹配$('.tb').each(function(index, tr) { alert($(this).find('td:nth-child(2)').text()); });的每个元素：

＆＃13;

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<table class="tb">
  <tr>
        <td>Calories </td>
        <td>TargetValue1</td>
    </tr>
    <tr>
        <td>Protein</td>
        <td>TargetValue2</td>
    </tr> 
    <tr>
        <td>Protein</td>
        <td>TargetValue3</td>
    </tr> 
</table>

＆＃13;

$env = $injector->make(Env::class);
$paths = array(__DIR__.'/../');
$isDevMode = isset($enf['DEVELOPMENT']);

// the connection configuration
$dbParams = array(
    'driver' => 'pdo_mysql',
    'host' => $env['DB_HOST'],
    'user' => $env['DB_USER'],
    'password' => $env['DB_PASS'],
    'dbname' => $env['DB_NAME'],
);

$config = Setup::createAnnotationMetadataConfiguration($paths, $isDevMode);

＆＃13;

＆＃13;

＆＃13;