get all li inside ul using jquery

i have a list with ul and li as:

<ul id="list1"> 
<li id="item-1">List Item 1</li> 
<li id="item-2">List Item 2</li> 
<li id="it开发者_StackOverflow中文版em-3">List Item 3</li> 
<li id="item-4">List Item 4</li> 
<li id="item-5">List Item 5</li> 
<li id="item-6">List Item 6</li></ul>

I need to get all the ids of the li inside ul as comma separated string using jquery like item-1,item-2,item-3,item-4,item-5,item-6

Use $.map for a nice and short way of doing that:

var liIds = $('#list1 li').map(function(i,n) {
    return $(n).attr('id');
}).get().join(',');