How can I merge properties of two JavaScript objects?

I need to be able to merge two (very simple) JavaScript objects at runtime. For example I'd like to: var obj1 = { food: 'pizza', car: 'ford' } var obj2 = { animal: 'dog' } obj1.merge(obj2); //obj1 now has three properties: food, car, and animal Is there a built in way to do this? I do not need recursion, and I do not need to merge functions, just methods on flat objects.