用索引填充ul列表

Question

I am having trouble populating a ul li with its index value.

My HTML below.

<ul>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
</ul>

My JS below.

$('document').ready(function(){
var indexus = $('li').index();
$('li').each(function(){
$('li').html(indexus);
});
});

JS Fiddle: http://jsfiddle.net/kuJWc/407/

I want to populate the li with its appropriate li index value, but I can only end up getting the index value of the latest (in this case 3). How would I go about looping in each index value so that each li shows the value of its own index number?

Answer 1

you should do like this:

$('li').each(function(){
    $(this).html($(this).index());
});

you were adding the index to all the li .. so istead of $(this) inside of the each, you were using $('li'). which adds the last value li index to all of them.

Answer 2

Try this:

$('document').ready(function(){
  $('li').each(function(){   // iterate through each `li`
    var $li = $(this);       // get the current `li` element
    var index = $li.index(); // get the current `li` index
    $li.html(index);         // set the `li`'s html to the index value
  });
});

I added some comments to help you understand what each step does, I hope that helps!

Answer 3

What about this:

$('document').ready(function(){
    var indexus = $('li');
    for (var i = 0; i <= indexus.length; i++) {
        $(indexus[i]).html(i);
    }
});

Here it works.

Answer 4

You can get an array of the ul's children and then iterate over each of the children with something like this:

var arr = $('ul').children();

for (var i = 0; i < arr.length; i++){
  $(arr[i]).html(i);
}