Question

I have a a function that takes a string like "obj.key.subkey.subsubkey":

function(obj, key) {
  return eval('obj.'+ key);
}

What would be a safe alternative to eval in this case or is eval fine? new Function won’t work in this case AFAIK. Maybe split and loop then?

Answer 1

I’m not sure you really need a function here. If you have the object and the key just use the key to return the property on the object.

obj[key]

If you must handle multiple keys:

function get(obj, key) {
  var keys = key.split(".");
  var tmp = obj;
  for (var x = 0; x < keys.length; x++){
     tmp = tmp[keys[x]];
  }
  return tmp;
}

Working Example: http://jsfiddle.net/H55ka/