Question

The output does not sort in ascending order. Here is the code and the output I am getting.

The actual output is:

Amy Jose Jeremy Alice Patrick 
Alan Amy Jeremy Helen Alexi

While the expected output is:

Amy, Alice, Jeremy, jose, Patrick
Alan, Amy, Alexi, Helen, Jeremy

The code is:

public class MyFriends
{
   static Set<String> names = new TreeSet<String>();

  public MyFriends()
   {
      super();
      names = new TreeSet<String>();
   }

  public static void exampleMethod()
   {
     String[] name1 = {"Amy", "Jose", "Jeremy", "Alice", "Patrick"};
     String[] name2 = { "Alan", "Amy", "Jeremy", "Helen", "Alexi"};

     for (int i = 0; i < name1.length; i++)
     {
         names.add(name1[i]);
     }

     for (String aString : name1)
     {
       System.out.print(" " + aString);
     }

     for (int i = 0; i < name2.length; i++)
     {
        names.add(name2[i]);
     }

     for (String bString : name2)
     {
       System.out.print(" " + bString); 
     }

   }    

Answer 1

You’re currently just writing out the arrays again… adding the contents of the array into a TreeSet isn’t going to change the array.

Instead of the two blocks writing out the arrays, you should have one, right at the end:

for (String name : names)
{
    System.out.print(" " + name); 
}

If you actually want two lines of output, you should use two TreeSet instances.

If you want to sort the arrays, you should just sort them in place. When you add a value to a TreeSet, it neither knows nor cares where it comes from. It’s just a reference to a string object (in this case).