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array question and confusion

Kay Liew
Ranch Hand

Joined: Dec 26, 2003
Posts: 112
I got so confused about this array question from KB book. Can someone please explain to me why B is correct and C is wrong ?? I really couldn't see why C is wrong.



A: b2[0][1] = b;
B: b[0][0]= b3;
C: b2[1][1][0]=b[0][0];
D: b2[1][2][0]=b;
E: b[0][1][0][0]=b[0][0];
F: b2[0][1]=big;
Suggested answer is A,B,E,F. B is the one that confused me the most. According to page 32. Wouldn't answer B contradicted with the explaination
below ?

int[][] books = new int [3][1];
int[] numbers = new int[6];
in aNumber = 7;
books[0] = aNumber; //NOT OK, expecting an int array instead of an int
books[0] = numbers; //OK, numbers is an int array.

Thx in advance,
Kay

( tags corrected and typos in code corrected)
[ December 07, 2004: Message edited by: Barry Gaunt ]

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Spaceact Wong
Greenhorn

Joined: Dec 05, 2004
Posts: 27
Originally posted by Kay Liew:
I got so confused about this array question from KB book. Can someone please explain to me why B is correct and C is wrong ?? I really couldn't see why C is wrong.

<CODE>
public class Test{
public staic void main(String [] args){
btye [][] big = new byte [7][7];
byte [][] b = new new byte [2][1];
byte b3 = 5;
byte b2 = [][][][] = new byte [2][3][2][2];
}
}
</CODE>

A: b2[0][1] = b;
B: b[0][0]= b3;
C: b2[1][1][0]=b[0][0];
D: b2[1][2][0]=b;
E: b[0][1][0][0]=b[0][0];
F: b2[0][1]=big;
Suggested answer is A,B,E,F. B is the one that confused me the most. According to page 32. Wouldn't answer B contradicted with the explaination
below ?

int[][] books = new int [3][1];
int[] numbers = new int[6];
in aNumber = 7;
books[0] = aNumber; //NOT OK, expecting an int array instead of an int
books[0] = numbers; //OK, numbers is an int array.

Thx in advance,
Kay


Hi,...
According to me, B is indeed correct and C is indeed wrong.


B: b[0][0]= b3;

B is the normal initialization of the array (in this case) and is the easiest part to be notified as correct answer!!!

C: b2[1][1][0]=b[0][0];

At the time you answer the question, did you regard answer 'A' as the correct answer??? I think if you put 'A' as the correct answer, then you should be able to know why C is incorrect, right?

C may only be correct, such as b2[1][1][0][0] = b[0][0];

E: b[0][1][0][0]=b[0][0];

By the way, is E shd be b2[0][1][0][0] = b[0][0];


MCP, MCAD .NET, MDSD .NET, MCDBA (SQL Server 2000) <br />SCJP 1.4, SCWCD 1.4, SCBCD 1.3
Ransika deSilva
Ranch Hand

Joined: Feb 18, 2003
Posts: 524
Hi,
Let me explain this to you. Now the answer A is correct. b2 is a 4 dimensional array and b is a 2 dimensional array. There you are assigning a 2d array to b2[0][1]. So the total number of Dimensions are 4. Which makes b2 a 4d array. So that is correct. All you have to remember is that, the number of Dimensions should be the same as to declared once you assign arrays.
Answer B is also correct cause you are just assigning a value (NOT an array) to the 0th location of the 0th row.
Answer C in INCORRECT. The 4th element is an array and NOT a value. But what happens at the Answer C is that it is assigning a value as the 4th Dimension. b2[1][1][0]= b[0][0]; b[0][0] is a value and NOT an array. So now the b2 has only 3 Dimensions, which is WRONG. It should be 4 Dimensions.
Hope you can figure out the rest. Just ask if you need any more clarifications. Cheers.......


SCJP 1.4, SCMAD 1.0<br />SCWCD, SCBCD (in progress)
Kay Liew
Ranch Hand

Joined: Dec 26, 2003
Posts: 112
Ransika,

Your explanation made better sense. It does reinforce the explaination from the book. Thanks for clearing up my doubts.

k
 
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