insert array in other array in to a for loop,first result repeated

Question

I have a problem when inserting an array into another array in this loop:

function formToArray(frm){
 var sAux={};
 var AnnotationsQuestion={};
 var AllAnnotationsQuestion=[];
 for (i = 0; i < frm.length; i++) {
 //next line dont work
 sAux['question_id'] = frm[i].name.substring(13)
 sAux['answer']=frm[i].value;
 sAux['id']=0;
 AnnotationsQuestion['AnnotationsQuestion']=sAux;
 AllAnnotationsQuestion.push(AnnotationsQuestion);
 }
return AllAnnotationsQuestion 
}

this returns the first result repeated x times

example of a return value

[{'AnnotationsQuestion':{'question_id':4,'answer':
'AA'....}},{'AnnotationsQuestion':{'question_id':4,'answer':
'AA'....}}]

what is the problem of this loop?

• Rikonator: You are not pushing a new object to AllAnnotationsQuestion on each iteration, rather a reference to the same object. Therefore, all elements of the returned array have the same value. If you do var sAux = {} at the beginning of your for loop, it should create a new object for that iteration, and then you will get unique values.
• Martin: Yes, I also thought the same but putting Saux var = {}, at the beginning of each iteration, I got the same result
• Rikonator: I do hope it was var sAux = {}; and not Saux var = {};... Anyway, look at the answer by @mplungjan, it's much cleaner.
• Martin: yes it is var sAux = {}; im sorry.
• Rikonator: I see. Yes, I'm sorry. The same object argument goes for AnnotationsQuestion as well. Once again, what you're pushing is a reference to a single object. Naturally, values are same across the board. You would have to do var AnnotationsQuestion = {}; at the beginning of each iteration, along with var sAux = {};. Check jsfiddle.net/rtSYC/3.

Answer 1

This is much safer and readable

DEMO

function formToArray(frm){
 var AllAnnotationsQuestion=[];
 for (var i = 0; i < frm.length; i++) {
 AllAnnotationsQuestion.push({
 'AnnotationsQuestion': {
 'question_id': frm[i].name.substring(13),
 'answer': frm[i].value, 
 'id':0 
 }
 });
 }
 return AllAnnotationsQuestion; 
}

• Martin: thanks for the answer, but I got this error with your solution 'Uncaught SyntaxError: Unexpected token : '
• Martin: This error is the chrome browser, in this line 'AnnotationsQuestion': {