scjp1.4 qtn on Mult-dimensional array

[Muthuvel Ramamoorthy]

Hi,

The answer for the following question is A, B, E, and F.
Could you please any one explain, how these answers are correct?

Thank you

Given the following,
1. public class Test {
2. public static void main(String [] args) {
3. byte [][] big = new byte [7][7];
4. byte [][] b = new byte [2][1];
5. byte b3 = 5;
6. byte b2 [][][][] = new byte [2][3][1][2];
7.
8. }
9. }
which of the following lines of code could be inserted at line 7, and still allow the code to
compile? (Choose four that would work.)
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. b2[0][1][0][0] = b[0][0];
F. b2[0][1] = big;

[Naseem Khan]

a, b, e, f is correct.
[ June 08, 2006: Message edited by: Naseem Khan ]

[lavanya sankuappan]

how come option c is wrong while e works fine?

[wise owen]

C. b2[1][1][0] = b[0][0];
"b[0][0]" is byte.

F. b2[0][1] = big;
"big" is two dimensional array.

[Naseem Khan]

[B]
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. b2[0][1][0][0] = b[0][0];
F. b2[0][1] = big; 
[/B]

Option C->>> required is one dimentional array but found primitive type.

Option E->>> required is primitive type type and found same.

[lavanya sankuappan]

thanks for your response guys

[sree latha]

Hi,

if you guys dont mind can u please explain the correct answers once again

thanks
sreelatha

[Naseem Khan]

public class Test {
  public static void main(String [] args) {
    byte [][] big = new byte [7][7];
    byte [][] b = new byte [2][1];
    byte b3 = 5;
    byte b2 [][][][] = new byte [2][3][1][2];
  }
}

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. b2[0][1][0][0] = b[0][0];
F. b2[0][1] = big;


A. b2[0][1]is two dimentional array and b is also 2-D array. TRUE

B. b[0][0] is primitive byte and b3 is alos primitive byte. Same type. TRUE

C. b2[1][1][0] is one dimentional array and b[0][0] is primitive type. Incompatible type. FALSE.

D. b2[1][2][0] is one dimentional array and b is 2-D array. Incompatible type. FALSE

E. b2[0][1][0][0] is byte primitive type and b[0][0] is also byte primitive type. TRUE

F. b2[0][1] is 2-D array and big is also 2-D array. So compatible type. TRUE

regards

[warren li]

I have a doubt here. E.g. answer E:
F. b2[0][1] = big;

b2 has already specified the sizes of its 4 dimensions.
and b2[0][1] will have size [1][2].
but big's size is [7][7] which is larger than b2[0][1].

how can 'big' fit into b2[0][1]? Or is this checked in run time but not in compile time? isn't array's size already known at compile time?