Using the Set interface in Java

JavaSet.java

package com.diycomputerscience;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import java.util.TreeSet;

public class JavaSet {

  public static void main(String args[]) {
    
    System.out.println("Adding words to a HashSet");
    Set<String> wordsInHashSet = createWordsInHashSet();
    System.out.println("Printing words from the HashSet");
    print(wordsInHashSet);
    
    System.out.println("");
    
    System.out.println("Adding words to a TreeSet");
    Set<String> wordsInTreeSet = createWordsInTreeSet();
    System.out.println("Printing words from the TreeSet");
    print(wordsInTreeSet);
  }
  
  private static Set<String> createWordsInTreeSet() {
    Set<String> set = new TreeSet<String>();
    set.add("one");
    set.add("two");
    set.add("three");
    set.add("four");
    set.add("five");
    set.add("three");
    return set;
  }

  private static Set<String> createWordsInHashSet() {
    Set<String> wordsInHashSet = new HashSet<String>();
    wordsInHashSet.add("one");
    wordsInHashSet.add("two");
    wordsInHashSet.add("three");
    wordsInHashSet.add("four");
    wordsInHashSet.add("five");
    wordsInHashSet.add("three");
    return wordsInHashSet;
  }
  
  private static void print(Set<String> set) {
    //Iterate across the Set and print it's contents
    Iterator<String> iter = set.iterator();
    while(iter.hasNext()) {
      String word = iter.next();
      System.out.println(word);
    }
  }
}