I have already covered normal way of iterating Map and list in Java. In this tutorial, we will see how to iterate (loop) Map and List in Java 8 using Lambda expression.
Iterating Map in Java 8 using Lambda expression
package com.beginnersbook; import java.util.HashMap; import java.util.Map; public class IterateMapUsingLambda { public static void main(String[] args) { Map<String, Integer> prices = new HashMap<>(); prices.put("Apple", 50); prices.put("Orange", 20); prices.put("Banana", 10); prices.put("Grapes", 40); prices.put("Papaya", 50); /* Iterate without using Lambda for (Map.Entry<String, Integer> entry : prices.entrySet()) { System.out.println("Fruit: " + entry.getKey() + ", Price: " + entry.getValue()); } */ prices.forEach((k,v)->System.out.println("Fruit: " + k + ", Price: " + v)); } }
Output:
Fruit: Apple, Price: 50 Fruit: Grapes, Price: 40 Fruit: Papaya, Price: 50 Fruit: Orange, Price: 20 Fruit: Banana, Price: 10
Iterating List in Java 8 using Lambda expression
package com.beginnersbook; import java.util.List; import java.util.ArrayList; public class IterateListUsingLambda { public static void main(String[] argv) { List names = new ArrayList<>(); names.add("Ajay"); names.add("Ben"); names.add("Cathy"); names.add("Dinesh"); names.add("Tom"); /* Iterate without using Lambda Iterator iterator = names.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next()); } */ names.forEach(name->System.out.println(name)); } }
Output:
Ajay Ben Cathy Dinesh Tom
SRIKANTH says
can you explain lamda expressions ?
Subbiah S says
Please go through this
https://beginnersbook.com/2017/10/java-lambda-expressions-tutorial-with-examples/