javascript - how to turn loop (for) into promise in java script -


i have implement java script request data server using ajax (xhr).

but somehow, loop not promise.

i tried implement promise alway failed.

this javascript want convert promise

    var resula = ajaxa(a);     for(resulta){        var resultb = ajaxb(url?param1=resulta.id);        for(resultb){             var resultc = ajaxc(url?param1=resulta.id¶m2=resultb.id);            for(resultc){            }          }      }

could please give me guide how turn javascript above promise ??

edited: here java script want use promise

var xhr = $.getjson('${pagecontext.request.contextpath}/someurl.action?');         console.log("after load ajax"); xhr.done(function(data){      (var = 0; < data.length; i++) {            var xhrpolygon =            $.getjson('${pagecontext.request.contextpath}/koordinat/getkoordinateaja.action?idarea='+data[i].id);                       xhrpolygon.done(function(resultdata){ if(resultdata.length>0){                              (var j = 0; j < resultdata.length; j++) {                                     var koordinat = [resultdata[j].arealng,resultdata[j].arealat];                                     console.log(koordinat);                              }                             }                         });     } });

javascript xhr isn't build on top of promises, new fetch here have documentation https://github.github.io/fetch/

if need create promise here have code

let promise = new promise((resolve, reject) => {    if(success){      resolve();    }    else{     reject() } });  promise.then(r => console.log(r), e => console.log(e));

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