Neelima,
If you write the code as shown below
You will get compile time error at LINE X saying b3 is not initialized. So you need to specify constant values to the array b3 or either allocate memory using new operator.
b3 = new byte[1][1]; and as far as the original question is concerned yes both b2 and b3 are two dimensional arrays.
A word of advice: If you are planning to give the certification , download java sdk from sun web site and try out the code. You need to have lot of coding practice, reading books is not just sufficient.
Good Luck !!!
Cheers,<br />Jay<br /> <br />(SCJP 1.4)<br />Heights of great men were not achieved in one day, they were toiling day and night while their companions slept.