Using variables with nested Javascript object

Question

Suppose I have this:

var a = { A : { AA : 1 }, B : 2 };

Is there a way for me to create a variable that could allow me to reference either

Answer 1

Actually no, because js object are seen as property bags and doing a[X] is for accessing first level properties only...

But you could wrap the logic a['A']['AA']; // 1 in a function that does the same, like this

//WARN... no undefined check here => todo !
function _(o, path) {
  var tmp = o
  for (var i=0 ; i < path.length ; i++) {
    tmp = tmp[path[i]]
  }
  return tmp
}

var r = _(a, ['A', 'AA'])

This is pretty much the same as other answers, but the difference is when dummy boy create object property name containing dots... Like var a = {"a.a" : 3 } is valid.

Now, such problem would occurs maybe more often now with the help of IndexedDB to store anything locally...