Accessing an element of a nested object using a variable for the key?

Question

Silly example:

<script>
var a = {
    'b' : {
        'c' : "success!!"
    }
};
var d = 'b.c';
</script>

How could I access success!! if I can't go for the obvious solution a.b.c or a['b']['c'], but instead have to use d? I tried a[d], which doesn't seem to do the trick. I also tried to fiddle with eval(). Is this even possible?

Answer 1

Try splitting

var a = {
    'b' : {
        'c' : "success!!"
    }
};
var d = 'b.c';

var splat = d.split('.');

console.log(a[splat[0]][splat[1]]);

Answer 2

If it's really necessary to have the keys in a string separated with a dot, I would use split and reduce:

var success = d.split(".").reduce(function (obj, key) {
  return obj[key];
}, a);