Array Flatten

array-flatten.js

(function (env, obj) {

var arrayType = '[object Array]';

function flatten (arr) {
	var flattened = [];
	var i = 0, l = arr.length;

	for(; i < l; i++) {
		var value = arr[i];
		
		if (obj.toString.call(value) === arrayType) {
			flattened = flattened.concat(flatten(value));
		} else {
			flattened.push(value);
		}
	}

	return flattened;
}

})(this, Object.prototype);