jquery filtering has + not

Question

Okay I have list items, some have a span, some not.
On my event I want to add the span when they don\'t have any yet.

has() works fine, but

Answer 1

Try this,

$("a.add-span").click(function() {
    $("li:not(:has(span))").each(function(index) {
        $(this).append($("").html("Newly Added Span"));
    });
});