Get Depth of an array.

arrayDepth.js

function depthOf(arr) {
    if(!Array.isArray(arr))
        throw "Not an Array"
    var depth = 1;
    var i;
    for(var i = 0; i< arr.length; i++){
        if (!Array.isArray(arr[i])) continue;

        if(Array.isArray(arr[i])){
            var depth = depthOf(arr[i]) + 1;
            depth = Math.max(depth, depth);
        }
    }
    return depth;
}

It there is a self-referencing object or array then this code will go into an endless loop.

In that case, we can take advantage of sets to see if there is a self-reference or not to fix the issue.