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Count the number of elements in a HashSet in Java
To count the number of elements in a HashSet, use the size() method.
Create HashSet −
String strArr[] = { "P", "Q", "R" };
Set s = new HashSet(Arrays.asList(strArr));Let us now count the number of elements in the above Set −
s.size()
The following is an example to count the number of elements in a HashSet −
Example
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
public class Demo {
public static void main(String[] a) {
String strArr[] = { "P", "Q", "R" };
Set s = new HashSet(Arrays.asList(strArr));
System.out.println("Elements: "+s);
System.out.println("Number of Elements: "+s.size());
}
}Output
Elements: [P, Q, R] Number of Elements: 3
Let us see another example −
Example
import java.util.*;
public class Demo {
public static void main(String args[]) {
// create a hash set
HashSet hs = new HashSet();
// add elements to the hash set
hs.add("B");
hs.add("A");
hs.add("D");
hs.add("E");
hs.add("C");
hs.add("F");
hs.add("K");
hs.add("M");
hs.add("N");
System.out.println("Elements: "+hs);
System.out.println("Number of Elements: "+hs.size());
}
}Output
Elements: [A, B, C, D, E, F, K, M, N] Number of Elements: 9
Updated on: 25-Jun-2020
3K+ Views
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