JAVA EXAMPLE PROGRAMS

JAVA EXAMPLE PROGRAMS

Checkout for Promo Codes

Java 8 - forEach method example with Map


forEach is a new method introduced in Java 8 to iterate over collections. Here is an example on forEach method to iterate over Map.

package com.java2novice.java8;

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

public class ForEachMapEx {

	public static void main(String a[]) {

		Map<String, String> countryMap = new HashMap<>();
		countryMap.put("India", "Delhi");
		countryMap.put("USA", "Washington, D.C.");
		countryMap.put("Japan", "Tokyo");
		countryMap.put("Canada", "Ottawa");

		// iterate through Map normal way
		ForEachMapEx.iterateMap(countryMap);

		// iterate through Map using forEach method
		ForEachMapEx.iterateMapUsingForEach(countryMap);
	}

	public static void iterateMap(Map<String, String> countryMap) {

		System.out.println("<----------Iterating in normal way------------->");
		for(Entry<String, String> entry:countryMap.entrySet()) {
			System.out.println("Country: "+entry.getKey()+" : Capital: "+entry.getValue());
		}
	}

	public static void iterateMapUsingForEach(Map<String, String> countryMap) {

		System.out.println("\n<----------Iterating using forEach method------------>");
		countryMap.forEach((k,v)->System.out.println("Country: "+k+" : Capital: "+v));

		countryMap.forEach((k,v)->{
			// you can implement some business logic here..



		});
	}
}

Output:
<----------Iterating in normal way------------->
Country: Canada : Capital: Ottawa
Country: USA : Capital: Washington, D.C.
Country: Japan : Capital: Tokyo
Country: India : Capital: Delhi

<----------Iterating using forEach method------------>
Country: Canada : Capital: Ottawa
Country: USA : Capital: Washington, D.C.
Country: Japan : Capital: Tokyo
Country: India : Capital: Delhi
 Next Program >>

Java 8 forEach method examples

  1. Java 8 forEach example with Map
  2. Java 8 forEach example with List
Knowledge Centre
Interface and its usage
Interface is similar to a class which may contain method's signature only but not bodies and it is a formal set of method and constant declarations that must be defined by the class that implements it. Interfaces are useful for declaring methods that one or more classes are expected to implement, capturing similarities between unrelated classes without forcing a class relationship and determining an object's programming interface without revealing the actual body of the class.
Famous Quotations
The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.
-- William Arthur Ward

About Author

I'm Nataraja Gootooru, programmer by profession and passionate about technologies. All examples given here are as simple as possible to help beginners. The source code is compiled and tested in my dev environment.

If you come across any mistakes or bugs, please email me to [email protected].

Most Visited Pages

Other Interesting Sites

Reference: Java™ Platform Standard Ed. 7 - API Specification | Java™ Platform Standard Ed. 8 - API Specification | Java is registered trademark of Oracle.
Privacy Policy | Copyright © 2020 by Nataraja Gootooru. All Rights Reserved.