import java.util.*;

public class TestSet {

public static void main (String[] args) {

Set<Integer> testSet = new TreeSet<Integer>();

//Set<Integer> testSet = new HashSet<Integer>();

//Set<Integer> testSet = new LinkedHashSet<Integer>();

testSet.add(1);

testSet.add(3);

testSet.add(5);

testSet.add(7);

boolean checkDuplicate = testSet.add(5);

if (!checkDuplicate)

System.out.println("No adding!");

System.out.println("Size now = " + testSet.size());

if (testSet.contains(7)) {

System.out.println("7 is in the set!");

} else {

System.out.println("7 is not in the set!");

}

testSet.remove(5);

if (testSet.contains(5)) {

System.out.println("5 is in the set!");

} else {

System.out.println("5 is not in the set!");

}

//1, 3, 7

for (int i : testSet)

System.out.println(i);

//Test iterator

//Iterator.next() method advances the iterator to the next element

Iterator iter = testSet.iterator();

System.out.println("Value returned by the current iterator = " + iter.next());

System.out.println("Value returned by the current iterator = " + iter.next());

}

}