Object is unsubscriptable
<p>I  would like to know what is "object is unsubscriptable" error. As I was coding I received this error and I don't really know what it means.</p>

<p>Here is a portion of the coding!</p>

<pre><code>function divide_all(x,y,z) {
    return x / z - y / z;
}
</code></pre>
