Question

Html代码

<div class="answer">
    <input type="checkbox" />
    <input type="checkbox" />
    <input type="checkbox" />
    <input type="checkbox" />
</div>
<div class="answer">
    <input type="checkbox" />
    <input type="checkbox" />
    <input type="checkbox" />
    <input type="checkbox" />
</div>
<button>check</button>

jQuery代码

$('button').click(function(){

    var checkedboxes = $('.answer :checkbox:checked').length;

    if (checkedboxes === 0){
        alert('At least 1 checkbox must be checked from this div!');
    }
});

但是我的代码没有检查每个<div class='answer'>

内的至少一个复选框

JS FIDDLE DEMO

Answer 1

尝试，

if ($('.answer').filter(function(){  return $(this).find(':checked').length === 0 }).length > 0 ) {
 alert('At least 1 checkbox must be checked from this div!');
}

DEMO

Answer 2

您可以遍历所有.answer并检查其中是否没有选中复选框：

$('button').click(function(){
    $('.answer').each(function() {
        if($(this).find(':checkbox:checked').length === 0) {
            alert('At least 1 checkbox must be checked from this div!');
        }
    });
});

<强> Fiddle Demo

Answer 3

试试这个：

$('button').click(function(){
  $('.answer').each(function() {
    if (!$(this).find('input:checked').length ) {alert('At least 1 checkbox must be checked from this div!');
        return false;
}});});

<强> Working Demo

Answer 4

选择器中的问题是您选择了所有答案.answers 要选择有问题的块，而不循环所有答案，选择器会更复杂：

$('button').click(function(){
  // check if there is an '.answer' which does NOT have checked checkbox.
  var checkedboxes = $(".answer:not(:has(> input:checkbox:checked))").length;

    if (checkedboxes > 0){
        alert('At least 1 checkbox must be checked from this div!');
    }
});

Fiddle Demo

每个div中必须至少检查一个复选框

4 个答案:

DEMO