A simple Java 8 tip to print the Array or List with index in the front. 1. Array with Index Generate the index with IntStream.range. JavaListWithIndex.java package com.mkyong.java8; import java.util.List; import java.util.stream.Collectors; import java.util.stream.IntStream; public class JavaArrayWithIndex { public static void main(String[] args) { String[] names = {"Java", "Node", "JavaScript", "Rust", "Go"}; List<String> collect = …
In Java 8, Consumer is a functional interface; it takes an argument and returns nothing. @FunctionalInterface public interface Consumer<T> { void accept(T t); } 1. Consumer Java8Consumer1.java package com.mkyong.java8; import java.util.function.Consumer; public class Java8Consumer1 { public static void main(String[] args) { Consumer<String> print = x -> System.out.println(x); print.accept("java"); // java } } Output java 2. …
In Kotlin, you can loop a Map via the following ways: 1. for loop val items = HashMap<String, Int>() items["A"] = 10 items["B"] = 20 for ((k, v) in items) { println("$k = $v") } 2. forEach items.forEach { k, v -> println("$k = $v") } 1. For Loop Loop a Map and filter it …
In Java 8, we can use the new forEach to loop or iterate a Map, List, Set, or Stream. Topics Loop a Map Loop a List forEach and Consumer forEach and Exception handling forEach vs forEachOrdered 1. Loop a Map 1.1 Below is a normal way to loop a Map. public static void loopMapClassic() { …