Example of constructor property

gistfile1.js

var F = function() {};  // This is a function object
var p = F.prototype;    // This is the prototype object associated with it
var c = p.constructor;  // This is the function associated with the prototype
c === F // => true, F.prototype.constructor === F fo any function

var o = new F();  // Create an object o of class F
o.constructor === F  // => true, the constructor property specifies the class