getJson同步

$.ajaxSettings.async = false;//在执行之前加$.ajaxSettings.async = false;  (同步执行) 

 function get_no_order_array() {
   var order_info = show_order();
   var order = [];
   $.ajaxSettings.async = false;//在执行之前加$.ajaxSettings.async = false;  (同步执行)
   $.getJSON("../JSON/customers.json", function (date) { //<span style="line-height: 1.5;">$.getJSON不懂的话可以看一下我之前的博客，或是专门学习一下  “JSON”</span>
 date["man"].forEach(function (person) {
       if (order_info.k_obj[person] == undefined) {
         order.push(person);
       }
     })
   });
   $.ajaxSettings.async = true;//执行你的代码之后及时恢复为$.ajaxSettings.async = true； （异步执行）
   return order;
 }