AngularJS form and null/empty values

Question

I am working with a somewhat dynamic AngularJS form. In other words, I am able to add rows of input fields, etc. So my approach was to start with a $scope.formData

Answer 1

function replacer(key, value) {
    if (value == "" || value == null) {
       return undefined;
    }
  return value;
}

var foo = {foundation: "", model: {year: 2015, price:null}, week: 45, transport: "car", month: 7};
foo = JSON.stringify(foo, replacer);
foo =JSON.parse(foo);
console.log(foo);