Learning RxJava

Making a Function a lambda

Lambdas can also implement single abstract methods that accept arguments and return an item. For instance, RxJava 2.0 (as well as Java 8) has a Function<T,R> type that accepts a T type and returns an R type. For instance, you can declare a Function<String,Integer>, whose apply() method will accept a String  and return an Integer. Here, we implement apply() by returning the string's length in an anonymous class, as shown here:

import java.util.function.Function;public class Launcher {    public static void main(String[] args) {        Function<String,Integer> lengthMapper = new Function<String,Integer>() {            @Override            public Integer apply(String s) {                return s.length();            }        };        Integer length = lengthMapper.apply("Alpha");        System ...