Array flattener [JS]

index.js

var flatten = function(array)
{
	var result = [];
	
	array.forEach(function(element) {
		if (element instanceof Array) {
			flatten(element).forEach(function(subElement) {
				result.push(subElement);
			}, this);
		} else {
			result.push(element);
		}
	}, this);
	
	return result;
}