jQuery - If UL exists and how many LI

Im looking for a way, in jQuery, to check if a UL exists AND if it does count the number of LI elements are contained within it.

The following jQuery loads a UL into a hidden DIV if there are new records to be fetched from the database:

j(".refreshMe").everyTime(5000,function(i){
    j.ajax({
      url: "refresh.php?latest="+className+"",
      cache: false,
      success: function(html){
        j(".refreshMe").html(html);
      }
    })
});

If a UL is returned I want to count how many LI elements are in the list,开发者_Python百科 then write that value to the page.

How can I achieve this in jQuery?

You can do it like this:

j(".refreshMe").everyTime(5000,function(i){
    j.ajax({
      url: "refresh.php?latest="+className+"",
      cache: false,
      success: function(html){
        alert($("li", html).length); //number of <li> found
        j(".refreshMe").html(html);
      }
    })
});

In your success handler just use the returned data as the context to look in, so $("li", html) only looks for <li> elements in the server response, and .length is the count found, you can take the value and place it where you want it in the page.