In knockout js I see View Models declared as either:

var viewModel { firstname: ko.observable("Bob") }; ko.applyBindings(viewModel ); 

or:

var viewModel = function() { this.firstname= ko.observable("Bob"); }; ko.applyBindings(new viewModel ()); 

What's the difference between the two, if any?

I did find this discussion on the knockoutjs google group but it didn't really give me a satisfactory answer.

I can see a reason if I wanted to initialise the model with some data, for example:

var viewModel = function(person) { this.firstname= ko.observable(person.firstname); }; var person = ... ; ko.applyBindings(new viewModel(person)); 

But if I'm not doing that does it matter which style I choose?

In knockout js I see View Models declared as either:

var viewModel = { firstname: ko.observable("Bob") }; ko.applyBindings(viewModel ); 

or:

var viewModel = function() { this.firstname= ko.observable("Bob"); }; ko.applyBindings(new viewModel ()); 

What's the difference between the two, if any?

I did find this discussion on the knockoutjs google group but it didn't really give me a satisfactory answer.

I can see a reason if I wanted to initialise the model with some data, for example:

var viewModel = function(person) { this.firstname= ko.observable(person.firstname); }; var person = ... ; ko.applyBindings(new viewModel(person)); 

But if I'm not doing that does it matter which style I choose?