Learning RxJava - Second Edition

withLatestFrom()

Similar to Observable.combineLatest(), but not exactly the same, is the withLatestFrom() operator. This will map each T emission with the latest values from other observables and combine them, but it will only take one emission from each of the other observables:

import io.reactivex.rxjava3.core.Observable;import java.util.concurrent.TimeUnit;public class Ch4_16 {    public static void main(String[] args) {        Observable<Long> source1 =                     Observable.interval(300, TimeUnit.MILLISECONDS);        Observable<Long> source2 =                            Observable.interval(1, TimeUnit.SECONDS);        source2.withLatestFrom(source1, (l1, l2) ->                              "SOURCE 2: " + l1 + " SOURCE 1: " + l2)               .subscribe(System.out::println);        sleep(3000);    }}

The output is as follows:

SOURCE 2: 0 SOURCE ...