JSON.parse for array of object

This works perfectly

    function myFunction(dataFromServer){
       var parsedJSON = JSON.parse(dataFromServer.d);
       for (var i=0;i<parsedJSON.length;i++) {
            alert(parsedJSON[i].Id);
         }
 }

But this doens't

    function myFunction(dataFromServer){
           var parsedJSON = JSON.parse(dataFromServer.d);
           for (var item in parsedJSON) {
               alert(item.Id);
         }
 }

You can just access them as you would any object:

var id = item.Id;
if (item.IsGood) { ... }

If you wish to enumerate them to use somehow, have a look at this SO question.