var startArray = [[1,2,[3]],4];
var endArray = [];
//Enter the first recurssion to flatten the array
flattenArray(startArray);
console.log('Start Array:      ' + startArray);
console.log('End Array:     ' + endArray);
function flattenArray(input)
{
	for (var i = 0; i < input.length; i++)
	{
		if (typeof(input[i]) === "object")
		{
    //Recursively loop until its no longer an array object
			flattenArray(input[i]);
		}
		else
		{
    //Once its no longer an array object, push the element into the endArray
			endArray.push(input[i]);
		}
	}
}