How to convert 1 to true or 0 to false upon model fetch

Here's another option that's longer but may be more readable:

Boolean(Number("0")); // false
Boolean(Number("1")); // true

Use a double not:

!!1 = true;

!!0 = false;

obj.isChecked = !!parseInt(obj.isChecked);

All you need is convert string to int with + and convert the result to boolean with !!:

var response = {"isChecked":"1"};
response.isChecked = !!+response.isChecked

You can do this manipulation in the parse method:

parse: function (response) {
  response.isChecked = !!+response.isChecked;
  return response;
}

UPDATE: 7 years later, I find Number(string) conversion more elegant. Also mutating an object is not the best idea. That being said:

parse: function (response) {
  return Object.assign({}, response, {
    isChecked: !!Number(response.isChecked), // OR
    isChecked: Boolean(Number(response.isChecked))
  });
}