Check if array[4][3][7][3] is defined
<p>When there is a single dimension array, it is easy to check whether it is defined, by either simple calling <code>arr[6]</code> which will return <code>undefined</code> if such property does not exist or calling <code>typeof arr[6] === undefined</code>.</p>

<p>The problem is, that in my case I have <code>arr[5][1][6][2][5][3][7]</code>, where <code>arr[5]</code> can be non existent, or <code>arr[5][1]</code>, etc. Which will naturally trigger error: <code>TypeError: Cannot read property [..]</code> One solution is to write many IF statements. However, is there any better solution, that'd simple allow me to check whether <code>arr[5][1][6][2][5][3][7]</code> is defined?</p>
