javascript - neither success nor error is working in jquery ajax -

i beginner jquery ajax. below ajax code working fine when using async: false, due problems in firefox removed after referring link(i facing same issue). not working. not showing errors.

here code:

try {     _ajaxcall = $.ajax({         url: url,         type: "post",         data: "drqlfragment=" + text,         //async : false,         cache: false,         headers: {             accept: "application/json",             contenttype: "application/x-www-form-urlencoded"         },         contenttype: "application/x-www-form-urlencoded",         //processdata : true,         success: function (data, textstatus, jqxhr) {             var resdata = data.suggestions;             (var = 0; < resdata.length; i++) {                 sugdata.push(resdata[i].keyword);             }         },         error: function (response) {             //error here             alert('hello');         }     }); } catch (e) {     alert(e); } 

the above code neither executing success nor error. tried catch error keeping try catch block no use.

the problem was doing manipulations outside success callback function. working fine when used async: false. means ajax call synchronous. when removed async: false, manipulations doing outside success callback function not working. problem because of asynchronous behaviour of ajax call. when calling ajax call asynchronously, not flow code priciple i.e step step , top bottom can happen anytime. so, not able desired output.

when replaced code manipulations in success callback, code working fine. @mccannf pointed problem in above comments. :).