What is the result of the following code?

Question

```
1 ArrayList mysteryArrayList = new ArrayList();
2 String output = "";
3
4 mysteryArrayList.add( "1" );
5 mysteryArrayList.add( "2" );
6 mysteryArrayList.add( "3" );
7 mysteryArrayList.add( "4" );
8 mysteryArrayList.add( "5" );
9 mysteryArrayList.remove( 1 );
10 mysteryArrayList.remove( 2 );
11
12 Iterator mysteryIterator = mysteryArrayList.iterator();
13
14 while ( mysteryIterator.hasNext() )
15 {
16 String currentElement = ( String ) mysteryIterator.next();
17
18 output += ( currentElement + " " );
19 }
20
21 JOptionPane.showMessageDialog( null, output, "Mystery",
22 JOptionPane.INFORMATION_MESSAGE );
```

Answer 1

This code creates an ArrayList, mysteryArrayList, and adds to it the Strings "1", "2", "3", "4" and "5", in that order. An item is then removed at index 1 (the String "2"). The ArrayList automatically updates the indices of the remaining items (now "1", "3", "4" and "5"). An item is then removed at index 2 (the value "4"). The ArrayList auto- matically updates the indices of the remaining items (now "1", "3" and "5"). An Iterator is then created and used to iterate through each element of mysteryArrayList. Each ele- ment’s value is added to String output, which is then displayed in a JOptionPane as "1 3
5".