jQuery所有类文本的总和为数字

Question

我希望将所有文本总结为类中称为“已发送”的数字，但当我提醒下面的代码时，它会输出零：

var sum = 0;            
var thedate = $(".date:contains('15th February 2012')");

   $(thedate).each(function() {              
    var sents = $(this).next('.sent').text();

    var sentsnumb = parseFloat(sents);

        sum += Number($(sentsnumb));

});
    alert(sum);

这是我的HTML：

<tr>
   <td class="date">15th February 2012</td>
   <td class="sent"> 5</td>
</tr>
<tr>
   <td class="date">15th February 2012</td>
   <td class="sent"> 5</td>
</tr>
<tr>
   <td class="date">15th February 2012</td>
   <td class="sent"> 10</td>
</tr>
<tr>
   <td class="date">15th February 2012</td>
   <td class="sent"> 10</td>
</tr>

上面所需的输出数字是“30”。

Answer 1

尝试这种方式： -

var sum = 0;            
var thedate = $(".date:contains('15th February 2012')");

   $(thedate).each(function() {              
    var sents = $(this).next('.sent').text();
    sum = sum + Number(sents);
});

alert(sum);​

实际问题是 $（sentsnumb）。它应该替换为 sentsnumb

Answer 2

试试这个：

var sum = 0;             
var thedate = $(".date:contains('15th February 2012')"); 

$(thedate).each(function() {               
   var sents = $(this).next('.sent').text(); 
   var sentsnumb = parseFloat(sents); 
   sum += sentsnumb; 
}); 
alert(sum); 

Answer 3

您无需通过jQuery $函数传递所有内容。

var sum = 0;
var thedate = $(".date:contains('15th February 2012')");

thedate.each(function() { // `thedate` is already a jQuery object, no need for `$()`
    var sents = $(this).next('.sent').text();

    var sentsnumb = parseInt(sents, 10); // use parseInt if your values don't have decimals

    sum += sentsnumb; // sentsnum is a float, do not use `$()` (or Number)
});

alert(sum);​

此外，您不能在<tr>之外添加<table>代码，请确保您的HMTL有效。