function Foo() {}
var foo = new Foo();
 
typeof Foo;             // == "function"
typeof foo;             // == "object"
 
foo instanceof Foo;     // == true
foo.constructor.name;   // == "Foo"
Foo.name                // == "Foo"    
 
Foo.prototype.isPrototypeOf(foo);   // == true
 
Foo.prototype.bar = function (x) {return x+x;};
foo.bar(21);            // == 42