LinkedHashSet: size()
import java.util.LinkedHashSet; public class Main { public static void main(String[] args) { LinkedHashSet<Integer> lhashSet = new LinkedHashSet<Integer>(); System.out.println("Size of LinkedHashSet : " + lhashSet.size()); lhashSet.add(new Integer("1")); lhashSet.add(new Integer("2")); lhashSet.add(new Integer("3")); System.out.println(lhashSet.size()); lhashSet.remove(new Integer("1")); System.out.println(lhashSet.size()); } }