copy - JavaScript stop referencing object after pass it to a function -

i know javascript passes objects reference , i'm having lot of trouble following code:

function dogradeassignmentcontent(dtos) {                     var x = 5;                     var allpages = [];                     var stage = new app.ui.popupdisplay.popupstageassignmentgrader(null, that);// pass launch element                     for(var = 0; < dtos[0].result.students.length; ++i) {                         var pagesset = [];                         for(var j = 0; j < dtos[0].result.questions.length; ++j) {                             var questionobject = jquery.extend(true, {}, new object());                             questionobject = dtos[0].result.questions[j];                             if(dtos[0].result.students[i].answers[j].assignmentquestionid === questionobject.questionid) {// expected, if not here wrong                                 questionobject.answer = dtos[0].result.students[i].answers[j].studentanswer;                                 questionobject.pointsreceived = dtos[0].result.students[i].answers[j].pointsreceived;                             } else {                                 var theanswer = findassociatedstudentanswer(questionobject.questionid, dtos[0].result.students[i].answers[j]);                                 if(theanswer !== null) {                                     questionobject.answer = theanswer.studentanswer;                                     questionobject.pointsreceived = theanswer.pointsreceived;                                 } else {                                     alert("unexpected error. please refresh , try again.");                                 }                             }                             pagesset[pagesset.length] = new app.ui.popupdisplay.stageassignmentgradingpages[dtos[0].result.questions[j].questiontype.charat(0).touppercase() + dtos[0].result.questions[j].questiontype.slice(1) + "questionassignmentgradingpage"](j + 1, questionobject);                         }                         var studentinfo = {};                         studentinfo.avatar = dtos[0].result.students[i].avatar;                         studentinfo.displayname = dtos[0].result.students[i].displayname;                         stage.addpageset(pagesset, studentinfo);                     }                     stage.launch();                 } 

first let me show result (dtos) looks can better understand how function parsing it:

the result (dtos) object , looks like:

• dtos array
• dtos[0], static here
• dtos[0].result, static here
• dtos[0].questions array
• dtos[0].questions.index0 - indexn. describes our questions, each 1 object
• dtos[0].students array
• dtos[0].students[0]-[n].answers array. each student array/object has answers array. each student have many elements in answers array there questions in dtos[0].questions. each element object

now in here create object stage. important things here has array called "this.studentspages". array have many entries there students in dtos[0].students.

so loop through loop disecting dtos array , creating pagesset array. here comes problem. on first iteration through loop create questionobject element. have tried doing var questionobject = {}, see attempt fix problem seeing, didn't work either.

so @ end of first iteration of outer loop call stage.addpageset, happens here:

var pageobject = [];             pageobject["questions"] = pageset;             pageobject["displayname"] = studentinfo.displayname;             this.studentspages[this.studentspages.length] = pageobject;              if(this.studentspages.length === 1) {// first time                 for(var = 0; < pageset.length; ++i) {                     this.addpage(pageset[i]);                 }             } 

the important thing take notice of here add pageobject on this.studentspages empty array before first call. pageobject has pageset plus little bit more information. remember, pageset object , passed reference.

on next iteration of loop, when hit line:

questionobject.answer = dtos[0].result.students[i].answers[j].studentanswer; 

it goes wrong. changes local copy of questionobject, changes copy of questionobjec passed addpageset , added studentspages array in first iteration. so, if had 2 students coming in, when said , done, studentspages hold 2 identical objects. should not true.

the problem questionobject in dogradeassignmentcontent function keeping reference object created on previous iteration , overrides on subsequent iterations.

what can fix this?

thanks help!

with out having looked @ closely believe need change following:

// before: var questionobject = jquery.extend(true, {}, new object()); questionobject = dtos[0].result.questions[j];  // after: var questionobject = jquery.extend(true, {}, dtos[0].result.questions[j]); 

i didn't closely if there other instances in code needs applied, core concept utilize jquery's deep copy generate duplicate of object not wish retain reference to.