Question

In JAVA,

Describe a scenario in which you would use a four-dimensional array. Clearly explain the purpose of each dimension of the array in that scenario.

Answer 1

Generally, each level of arrays means to have the content n-fold. That means

• int x[4] are 4 blocks, each of them containing an int.
• int x[5][4] are 5 blocks, each of them containing an int[4].
• int x[3][5][4] are 3 blocks, each of them containing an int[5][4].
• int x[2][3][5][4] are 2 blocks, each of them containing an int[3][5][4].

How you are referring to them is up to you, but for better understanding, you have something like

• COLUMN for the last one
• ROW for the second-last one
• PAGE for the third-last one

Till here, I read it somewhere. In order to stay here, we can as well define

• BOOK for the fourth-last one

You don't need to imagine in high spatial dimensions, just think of it as a fern leaf.

The main stalk is your first array, with each branch being an item that it is storing. If we look at a branch this is your second dimension. It has a similar structure of smaller branches coming of it representing its data. These in turn have their own small branches which continues until we get to the tiny leaves representing the data of the inner most or highest dimension array.

You can see this building up if you declare each level with its own name. Here I am reusing each level varible to minimise the code:

leaf = 2;
tinyBranch = [leaf, leaf, leaf];
middleBranch = [tinyBranch, tinyBranch, tinyBranch];
bigBranch = [middleBranch, middleBranch, middleBranch];
mainBranch = [bigBranch, bigBranch, bigBranch];