AJAX 异步传数组时候，后台接收不到！

var ids= [];
$.ajax({ 
        url: ‘xxxx.do‘, 
       data: { ids: ids}, 
       dataType: "json", 
       type: "POST", 
       success: function (responseJSON) { 
                alert(‘Ok‘); 
       } 
});

$.ajax({ 
    url: ‘xxxx.do‘, 
    data: { ids: ids}, 
    dataType: "json", 
    type: "POST", 
    traditional: true,//这里设为true就可以了
    success: function (responseJSON) { 
        alert(‘Ok‘); 
    } 
});