title: Get keys of JSON object from inner levels
body: <p>I have problem fetching key values of inner levels of object.</p>
  
  <p>This is the sample object</p>
  
  <pre><code>{  
  "dataset":{  
    "Categories":[  
       {  
          "Desserts":[  
             "Sweets",
             "Ice Creams",
             "Pastry",
             "Moose",
             "Jelly",
             "Donut",
             "Custard",
             "Puddings",
             "Cookies",
             "Pies"
          ]
       },
       {  
          "Juices and Beverages":[  
             "Cold",
             "Hot",
             "Fresh",
             "Mocktail",
             "Sodas"
          ]
       },
       {  
          "Indian Breads":[  
             "Plain",
             "Stuffed"
          ]
       },
       {  
          "Salads":[  
             "Green",
             "Vegetable",
             "Fruit"
          ]
       },
       {  
          "Soups":[  
             "Clear",
             "Thick"
          ]
       }
    ]
    }
   }
  </code></pre>
  
  <p>I tried interating through the object on the outer level.</p>
  
  <pre><code>for(var k in dataset.Categories)
      categories.push(k);
  </code></pre>
  
  <p>But I get the result as 0,1,2,3,4.</p>
  
  <p>How do I get the key values a level inside? Like "Desserts","Juices and Beverages",....</p>