Question

我需要知道每个<div>中有多少<li>个元素。就这样：

<ul>
   <li>
      <div> Some image 1 </div>
      <div> Some image 2 </div>
      <div> Some image 3 </div>
   </li>
   <li>
      <div> Some image 4 </div>
      <div> Some image 5 </div>
   </li>
   <li>
      <div> Some image 6 </div>
      <div> Some image 7 </div>
      <div> Some image 8 </div>
      <div> Some image 9 </div>
   </li>
</ul>

功能的输出：

First <li> has 3 <div>
Second <li> has 2 <div>
Third <li> has 4 <div>

Answer 1

var lengths = $('li').map(function(){
    return $(this).find('div').length;
}).get();

Live DEMO

<强>注释：

// Make an array when the input for every iteration is a <li>
$('li').map(

// Every element in the array is the amount <div>s inside the current <li>
    return $(this).find('div').length;

// Produce the arry.
.get();

如果您想制作类似于您想要的东西轻松：

$('li').each(function() {
    var length = $(this).find('div').length;
    $('<div> ' + length + ' li has ' + length + 'divs </div>').appendTo('#output');
});

Live DEMO

输出：

3 li has 3divs
2 li has 2divs
4 li has 4divs

Answer 2

给定代表<li>，item的jQuery对象，您可以通过执行以下操作找出它包含的<div>个数：

item.find('div').length

但如果你想要一个具有完全输出的函数，你需要一个数字→英文库。或者，如果您只有三个，请将<ul>作为list并执行此操作：

var items = list.find('li');

'First <li> has ' + items.eq(0).find('div').length + ' <div>';
'Second <li> has ' + items.eq(1).find('div').length + ' <div>';
'Third <li> has ' + items.eq(2).find('div').length + ' <div>';

Answer 3

$('li').each(function() {
    console.log($('div', this).length);
});

<强> jsFiddle example

Answer 4

$('li').each(function(i){
    console.log('<li> ' + i + ' has ' + $(this).children('div').length + 'divs');
});

计算<li> </li> </div>中<div>元素的数量

4 个答案: