How to check whether HashMap is empty or not ?

In this article, we will discuss and understand with a program to check whether HashMap is empty or not

In earlier article, we have seen how to check whether HashMap contains particular key/value or Not ? Read below articles for more details with example

To check whether HashMap is empty or not :

Method signature:

public boolean isEmpty();

Above method is used to check whether HashMap is empty or not from invoking Map object
It can be HashMap or LinkedHashMap or TreeMap
Returns true, if Map is empty
otherwise return false

HashMapIsEmptyOrNot.java

package in.bench.resources.collection;

import java.util.HashMap;

public class HashMapIsEmptyOrNot {

	public static void main(String[] args) {

		// creating empty HashMap object of type <String, String>
		HashMap<String, String> hashMap = new HashMap<String, String>();

		// checking empty even before adding any Key-Value pairs
		boolean isEmpty1 = hashMap.isEmpty();

		System.out.println("1. Checking Empty"
				+ " before adding any entries : " + isEmpty1);

		// adding key-value pairs to HashMap object
		hashMap.put("Google", "Sundar Pichai");
		hashMap.put("Facebook", "Mark Zuckerberg");
		hashMap.put("LinkedIn", "Reid Hoffman");
		hashMap.put("Apple", "Steve Jobs");
		hashMap.put("Microsoft", "Bill Gates");

		// checking empty adding few entries
		boolean isEmpty2 = hashMap.isEmpty();

		System.out.println("\n2. Checking Empty"
				+ " before adding any entries : " + isEmpty2);
	}
}

Output:

1. Checking Empty before adding any entries : true

2. Checking Empty before adding any entries : false

References:

Happy Coding !!
Happy Learning !!

BenchResources.Net

Java tutorial for beginners

How to check whether HashMap is empty or not ?

To check whether HashMap is empty or not :

HashMapIsEmptyOrNot.java