on的用法问题

Question

$('#menutest2').live('hover', function() {
  alert ("有效"); 
});用live给元素加事件

Answer 1

$(document).on("mouseenter","#menutest2", function(){
                  
                   alert ("in");
 
  });
$(document).on("mouseleave","#menutest2", function(){
    
    alert ("out");});

Answer 2

<script>
$(document).ready(function(e) {
    $(document).on('mouseover','#menutest2', function(){     
        alert ("有效");
});
});
</script>