jQuery的總和

Question

我期待總結所有文字稱爲類內部編號「發送」，但是當我提醒下面的代碼它給人的零輸出：

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); 

這裏是我的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> 

從上面的所需輸出將是數字「30」。

Answer 1

試試這個方法： -

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);​ 

實際的問題是$（sentsnumb）。它應與sentsnumb

Answer 2

試試這個來代替：

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

你並不需要通過jQuery的$函數傳遞的一切。

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);​ 

而且，你不能有一個<table>之外<tr>代碼，請確保您的HMTL是有效的。