src/main/java/io/reactivex/Observable.java
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    @NonNull
    public static <T> Observable<T> fromArray(T... items) {
        ObjectHelper.requireNonNull(items, "items is null");
        if (items.length == 0) {
            return empty();
        } else
        if (items.length == 1) {
            return just(items[0]);
        }
        return RxJavaPlugins.onAssembly(new ObservableFromArray<T>(items));
    }
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    @NonNull
    public static <T> Observable<T> fromArray(T... items) {
        ObjectHelper.requireNonNull(items, "items is null");
        if (items.length == 0) {
            return empty();
        } else
        if (items.length == 1) {
            return just(items[0]);
        }
        return RxJavaPlugins.onAssembly(new ObservableFromArray<T>(items));
    }
Converts an Array into an ObservableSource that emits the items in the Array.
<p>
<img width="640" height="315" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/from.png" alt="">
<dl>
<dt><b>Scheduler:</b></dt>
<dd>{@code fromArray} does not operate by default on a particular {@link Scheduler}.</dd>
</dl>

@param items
the array of elements
@param <T>
the type of items in the Array and the type of items to be emitted by the resulting ObservableSource
@return an Observable that emits each item in the source Array
@see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>