What is format of object JS? : <p>There is an array:</p>

<pre><code>var data = data.addRows([
        ['Nitrogen', 0.78],
        ['Oxygen', 0.21],
        ['Other', 0.01]
      ]);
</code></pre>

<p>What does it mean? Arrays in array? What is it <code>['Nitrogen', 0.78]</code> ? Why <code>[]</code> brackets?</p>

<p>I tried to reproduce this like:</p>

<pre><code>var arr = [];
arr.push({'Oxygen', 0.21});
</code></pre>
