title: PHP get json object name
body: <p>I have json array like that</p>
  
  <pre><code>{
    "STATUS": "SUCCESS",
    "MESSAGE": "",
    "DATA": {
      "list": [
        {
          "val0": {
            "hidden": "0",
            "rate": "10"
          }
        },
        {
          "val1": {
            "hidden": "0",
            "rate": "20"
          }
        }
      ],
      "status": "Provisioned"
    }
  }
  </code></pre>
  
  <p>I want to get the object name of <code>DATA&gt;list&gt;</code>. 
  I tried with <code>get_class($list[0])</code> but the output is <code>stdClass</code>. Output should be <code>val0</code>.How can I try. Please help</p>