What is a good unique way to type check?

Question

One simple approach used in libraries such as trunk:

typeof o === type; 

ES5 suggests using something similar to

 (Object.prototype.toString.call(o) === '[object ' + type + ']'); 

and finally, SO users shared: ( getType code overview )

 o.constructor === type; 

Here are three fundamentally different ways.

• using typeof
• using toString
• using constructor property

I would like to use these 3 methods to write a generic checkType method.

Any advice on how to best combine them logically or why is there can be in many ways.

Answer 1

Something will help here: http://javascriptweblog.wordpress.com/2011/08/08/fixing-the-javascript-typeof-operator/

Answer 2

Here is a good comparison 3.

http://jsperf.com/constructor-vs-typeof-vs-tostring