title: Replacing a property value in JSON
body: <p>If I have a JSON structure that looks something like this:</p>
  
  <pre><code>var user = {
      map: {
          width: 785,
          height: 791
      },
      image: {
          name: "image.png",
          size: {width:32}
      },
      properties:[{
          firstName: "Bob",
          lastName: "Jones",
      }]
  };
  </code></pre>
  
  <p>How would I change (after creation) the value of the <code>firstName</code> property to "Jane"?</p>
  
  <p>I am fairly new to JSON, and I'm just trying to figure out how to make this one change for now.  Any help would be greatly appreciated.</p>