title: How to find a particular JSON value by key?
body: <p>There is a JSON like this:</p>
  <pre><code>{
    &quot;P1&quot;: &quot;ss&quot;,
    &quot;Id&quot;: 1234,
    &quot;P2&quot;: {
        &quot;P1&quot;: &quot;cccc&quot;
    },
    &quot;P3&quot;: [
        {
            &quot;P1&quot;: &quot;aaa&quot;
        }
    ]
  }
  </code></pre>
  <p>How can I find all <code>P1</code>'s value without it iterating all JSON?</p>
  <p>P.S.: <code>P1</code> can be <em>anywhere</em> in the JSON.</p>
  <p>If no method can do this, can you tell me how to iterate through the JSON?</p>