How to create an undefined value in a JSON Object in Ruby/Rails
<p>I am trying to build a JSON object which is built in Rails.</p>

<p>My object is:</p>

<pre><code>person = {name: "david", age: 25, address: nil}
</code></pre>

<p>but the address appears as null and not undefined</p>

<p>person.to_json ======></p>

<pre><code>{name: "david", 
 age: 25, 
 address: null  &lt;---- I want this to be undefined
}
</code></pre>