title: Get keys in JSON
body: <p>I get the following JSON result from an external system:</p>
  
  <pre><code>{
    "key1": "val1",
    "key2": "val2",
    "key3": "val3"
  }
  </code></pre>
  
  <p>Now I want to display all keys and all values by using JSONPath. So I am looking for something to get key1, key2 and key3 as a result. Additionally I would like to use the index of a property, e. g. <code>$....[2].key</code> to get "key3" etc.
  Is there a way to do something like this?</p>