zipWithIndex

Zips elements of current flow with its indices.

Fan-in operators

Signature

Source.zipWithIndexSource.zipWithIndex Flow.zipWithIndexFlow.zipWithIndex

Description

Zips elements of current flow with its indices.

See also:

• zip
• zipAll
• zipWith

Example

Scala

copysourceimport akka.stream.scaladsl.Source
import akka.stream.scaladsl.Sink

    Source(List("apple", "orange", "banana")).zipWithIndex.runWith(Sink.foreach(println))
    // this will print ('apple', 0), ('orange', 1), ('banana', 2)

Java

copysourceimport akka.stream.javadsl.Keep;
import akka.stream.javadsl.Source;
import akka.stream.javadsl.Sink;

import java.util.*;

Source.from(Arrays.asList("apple", "orange", "banana"))
    .zipWithIndex()
    .runForeach(System.out::println, system);
// this will print ('apple', 0), ('orange', 1), ('banana', 2)

Reactive Streams semantics