JavaScript data types

types.js

//Thanks to perfectionkills.com <http://perfectionkills.com/instanceof-considered-harmful-or-how-to-write-a-robust-isarray/>
__getClass = function(val) {
	return Object.prototype.toString.call(val)
		.match(/^\[object\s(.*)\]$/)[1];
};

var whatis = function(val) {

	if(val === undefined)
		return 'undefined';
	if(val === null)
		return 'null';
		
	var type = typeof val;
	
	if(type === 'object') {
		type = __getClass(val).toLowerCase();
	}
	
	if(type === 'number') {
		if(val.toString().indexOf('.') > 0)
			return 'float';
		else
			return 'integer';
	}
	
	return type;
};


var isSet = function(val) {
	return (val !== undefined) && (val !== null);
};


var isEmpty = function(obj) {
	if (obj.length && obj.length > 0)
		return false;

	for (var key in obj) {
		if (hasOwnProperty.call(obj, key))
			return false;
	}
	return true;
};

var is = function(obj, type) {
	if (type === 'number')
		return isNumber(obj);
	if (whatis(obj) === type)
		return true;
	if (type === 'empty')
		return isEmpty(obj);
	if (type === 'set')
		return isSet(obj);
	return false;
};

var isArray = function(val) {
	return is(val, 'array');
};

var isNumber = function(val) {
	if (isNaN(val))
		return false;
		
	var type = typeof val;
	if (type === 'object')
		type = __getClass(val).toLowerCase();
		
	return type === 'number';
};

var isInt = function(val) {
	return is(val, 'integer');
};

var isFloat = function(val) {
	return is(val, 'float');
};

var isString = function(val) {
	return is(val,'string');
};

var isObject = function(val) {
	return is(val, 'object');
};

var isFunction = function(val) {
	return is(val, 'function');
};

var isDate = function(val) {
	return is(val,'date');
};

var isBool = function(val) {
	return is(val, 'boolean');
};

var isRegExp = function(val) {
	return is(val, 'regexp');
};