asynchronous - rxjava merge observables of different type

Question

I'm new to rxjava. I need to combine two observables that emit objects of different type. Something like Observable<Milk> and Observable<Cereals> and get a Observable<CerealsWithMilk>. I couldn't find any operator for something like this. What would be the rx way of doing something like this? Note that Milk and Cereals are async.

Answer 1

It's hard to say without knowing exactly what you need, but possibly zip() or combineLatest().

zip will take both Observable<Milk> and Observable<Cereals> and let you combine them into CerealsWithMilk via a provided function. This emits a new CerealsWithMilk each time you get get both a Milk and a Cereals.

combineLatest is similar to zip except it will emit a new CerealsWithMilk even if just a new Milk or just a new Cereals is emitted.