HashMap
Get size of HashMap example
With this example we are going to demonstrate how to get the size of a HashMap, that is the number of key value pairs that the HashMap contains. In short, to the size of a HashMap you should:
- Create a new HashMap.
- Populate the hashMap with elements, with the
put(K key, V value)
API method of HashMap. - Invoke the
size()
API method of the HashMap. It will return the int number of key value pairs stored in the hashMap.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core; import java.util.HashMap; public class SizeHashMap { public static void main(String[] args) { // Create a HashMap and populate it with elements HashMap hashMap = new HashMap(); hashMap.put("key_1","value_1"); hashMap.put("key_2","value_2"); hashMap.put("key_3","value_3"); // int size() operation returns the number of key value pairs stored in HashMap System.out.println("Size of HashMap : " + hashMap.size()); } }
Output:
Size of HashMap : 3
This was an example of how to the size of a HashMap in Java.