Answer:

Yes, just as for 1D arrays.

If you want a collection of a variety of types, you probably want to use a class to contain them, not an array.

2D Array of int

The following program creates a 2D array of int that implements the gradeTable example. Details about declaring and constructing 2D arrays will be explained later.

RowCol
01234
0 99 42 74 83 100
1 90 91 72 88 95
2 88 61 74 89 96
3 61 89 82 98 93
4 93 73 75 78 99
5 50 65 92 87 94
6 43 98 78 56 99
class gradeExample { public static void main( String[] arg ) { // declare and construct a 2D array int[][] gradeTable = { {99, 42, 74, 83, 100}, {90, 91, 72, 88, 95}, {88, 61, 74, 89, 96}, {61, 89, 82, 98, 93}, {93, 73, 75, 78, 99}, {50, 65, 92, 87, 94}, {43, 98, 78, 56, 99} }; System.out.println("grade 0,0: " + gradeTable[0][0]); System.out.println("grade 2,4: " + gradeTable[2][4]); gradeTable[5][3] = 99 ; int sum = gradeTable[0][1] + gradeTable[0][2] ; System.out.println( "sum: " + sum ); } }

The declaration of gradeTable uses an initializer list as a short-cut way to create a 2D array object and place values into it. The list contains 7 rows each separated by a comma; each row is a list of values.

QUESTION 6:

What does the program print out?