Assigning a string with a null means that the String contains no reference value. Also, you cannot assign more values more than the string length.
Java supports the class ArrayList, which is an array that is expandable if it needs to be expandable. You can learn more about it here:
http://java.sun.com/j2se/1.3/docs/ap...ArrayList.html
It also as neat methods that can add, delete, etc values at certain indexes.
Cheers.