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/* Get Size of Java HashMap Example This Java Example shows how to get the size or nubmer of key value pairs stored in HashMap using size method. */ import java.util.HashMap; public class GetSizeOfHashMapExample{ public static void main(String[] args) { //create HashMap object HashMap hMap = new HashMap(); /* To get the size of HashMap use int size() method of HashMap class. It returns the number of key value pairs stored in HashMap object. */ System.out.println("Size of HashMap : " + hMap.size()); //add key value pairs to HashMap using put method hMap.put("1","One"); hMap.put("2","Two"); hMap.put("3","Three"); System.out.println("Size of HashMap after addition : " + hMap.size()); //remove one element from HashMap using remove method Object obj = hMap.remove("2"); System.out.println("Size of HashMap after removal : " + hMap.size()); } } /* Output would be Size of HashMap : 0 Size of HashMap after addition : 3 Size of HashMap after removal : 2 */ |
simple example to understand the HashMap basic cocept