Question

以下是我的结构。

<span class="mrQuestionTable">                                            
    <span id="Cell.0.0">
        <input type="checkbox" name="_QC05_C__1" id="_Q0_C0" class="mrMultiple" value="__1"/> 
        <span class="mrMultipleText" style="">Mobile-related fraud (Fraud via mobile channels)</span>
    </span>

    <span id="Cell.0.1">
        <input type="checkbox" name="_QC05_C__2" id="_Q0_C1" class="mrMultiple" value="__2"/>
        <span class="mrMultipleText" style="">Cost (managing, implementation related costs)</span>
    </span>
</span>

我使用下面的代码来计算长度。一旦我点击复选框，它显示我的长度为0.相反它应该显示1.请让我知道为什么会发生这种情况？

alert($('.mrMultiple:checkbox:checked').length);

Answer 1

试试这个：

＆＃13;

$('.mrMultiple').on('change', function() {

  alert($('.mrMultiple:checked').length);

});

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<span class="mrQuestionTable">                                            
<span id="Cell.0.0">
<input type="checkbox" name="_QC05_C__1" id="_Q0_C0" class="mrMultiple"
value="__1"/>    
<span class="mrMultipleText" style="">Mobile-related fraud (Fraud via mobile 
channels)</span>
</span>
<span id="Cell.0.1">
<input type="checkbox" name="_QC05_C__2" id="_Q0_C1" class="mrMultiple"  
value="__2"/>
<span class="mrMultipleText" style="">Cost (managing, implementation 
related costs)</span>
</span>
</span>

＆＃13;

Answer 2

我相信你只想在点击一个复选框后检查复选框的长度。否则，警报功能将在页面加载时运行，并且不会检查任何内容。

$(".mrMultiple").on("click", function() 
   alert($('.mrMultiple:checked').length);
}

Answer 3

计算页面中存在的复选框数

var c=$('input[type=checkbox]').length;

计算页面中选中的复选框数量

var cc=$('input[type=checkbox]:checked').length

Answer 4

您需要将其置于点击功能中，或者无论您点击多少次，它都只会运行一次。

$(document).ready(function() {
  $("input").on("click", function() {
    console.log($('.mrMultiple:checkbox:checked').length);
  });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<span class="mrQuestionTable">                                            
  <span id="Cell.0.0">
    <input type="checkbox" name="_QC05_C__1" id="_Q0_C0" class="mrMultiple"
    value="__1"/>    
    <span class="mrMultipleText" style="">Mobile-related fraud (Fraud via mobile 
    channels)</span>
</span>
<span id="Cell.0.1">
    <input type="checkbox" name="_QC05_C__2" id="_Q0_C1" class="mrMultiple"  
    value="__2"/>
    <span class="mrMultipleText" style="">Cost (managing, implementation 
    related costs)</span>
</span>
</span>

无法计算使用jquery代码检查的复选框数

4 个答案: