title: How to access nested JSON object key and values
body: <p>I am trying to access the key and values of my nested array like this:</p>
  
  <pre><code>var obj = $.getJSON("mydata.json", function() {
      console.log( "load success" );
  });
  
  Object.keys(obj[2].type).forEach(function(key) {
      console.log(key, obj[key]);
  });
  </code></pre>
  
  <p>But I get an error.</p>
  
  <p>Here's the structure of the JSON file:</p>
  
  <pre><code>{
  "nodes": [
      {
          "nd": "nd1",
          "cat": "cat1"
      }
  ],
  "links": [
      {
          "id": 100
      }
  ],
  "types": [
              {
                  "type": "one",
                  "image": "image001"
              },
              {
                  "type": "two",
                  "image": "image002"
              },
              {
                  "type": "three",
                  "image": "image003"
              }
          ]   
  </code></pre>
  
  <p>}</p>
  
  <p>My goal is to get a list of values of:</p>
  
  <blockquote>
    <p>one two three</p>
  </blockquote>