two dimensional arrays

Question 1

multidimensional array

Answer 1

arrays of arrays

Question 2

how java stores 2-dim arrays

Answer 2

array of array references

Question 3

create a rectangular 2-dim array (primitive)

Answer 3

char[][]a=new char[5][8];

break down:
> char is the type (an array of arrays of characters)
> a is the name
> 5 is the length of the array of array references
> 8 is the length of the arrays the original array is pointing to

Question 4

what does the heap look like

Answer 4

an array of array references that point to individual arrays

Question 5

char[][]a=new char[5][8];

a.length = ?

Answer 5

a.length = 5
a[1].length = 8

Question 6

iterate row by row

Answer 6

for(introw = 0; row < a.length; row++) { 
for(intcol = 0; col < a[row].length; col++) {
a[row][col] = ‘ ’;

Question 7

ragged array

Answer 7

a 2-dim array with arrays of different sizes

Question 8

crate a ragged 2-dim array

Answer 8

char[][]a=new char[3][];
a[0]=new char[8];
a[1]=new char[0];
a[2]=null;

Question 9

1-dim initializer

Answer 9

int[ ] quizScoresOne= { 90, 82, 75, 66 };

Question 10

create a ragged 2-dim array (primitive)

Answer 10

char[][]a=new char[3][];
a[0]=new char[8];
a[1]=new char[0];
a[2]=null;

Question 11

2-dim initializer

Answer 11

int[ ][ ] quizScoresTwo= { { 90, 82, 75, 66 }, { 85 }, { 45, 77, 99 } };

Question 12

create a 2-dim array (objects, nonprimative)

Answer 12

ObjectType [][] var=new ObjectType[MAXROW][MAXCOL];