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

$("a.add-span").click(function() {
    $("li").each(function(index) {
       if ($(this).children('span').length === 0){
         $(this).append('new span<\/span>');
       }
    })    
})

With children() method, the length property is used to check whether or not a span already exits and if it doesn't, one is added/appended.

More Info:

• http://api.jquery.com/length/
• http://api.jquery.com/children/