title: How to access sub-values of a multi-dimensional object
body: <p>I have a multi-dimensional object like this one:</p>
  
  <pre><code>var map = {
      "a": {
          "aa": {
              "aaa":  "red",
              "aab":  "green"
          },
          "ab": "blue"
      }
      "b": {
          "ba": "orange"
      }
  }
  </code></pre>
  
  <p>What I need is a function that would allow something such like:</p>
  
  <pre><code>var foo = getSubValue(map, "a.ab"); // "blue"
  </code></pre>
  
  <p>The second parameter of this sample has to be a string. I can't use the following:</p>
  
  <pre><code>var foo = map.a.ab
  </code></pre>
  
  <p>Any Idea of how to proceed, or of an existing implementation ?
  Thanks for your help.</p>