Introduction to Java Programming, AP Version,
Y. Daniel Liang
This quiz is for students to practice. A large number of additional quiz is available for instructors from the Instructor's Resource Website.
Chapter 8 Multidimensional Arrays
Section 8.2 Two-Dimensional Array Basics
8.1
Which of the following statements are correct?
A.
char[][] charArray = {'a', 'b'};
B.
char[2][2] charArray = {{'a', 'b'}, {'c', 'd'}};
C.
char[2][] charArray = {{'a', 'b'}, {'c', 'd'}};
D.
char[][] charArray = {{'a', 'b'}, {'c', 'd'}};
8.2
Assume double[][] x = new double[4][5], what are x.length and x[2].length?
A.
4 and 4
B.
4 and 5
C.
5 and 4
D.
5 and 5
8.3
What is the index variable for the element at the first row and first column in array a?
A.
a[0][0]
B.
a[1][1]
C.
a[0][1]
D.
a[1][0]
8.4
When you create an array using the following statement, the element values are automatically initialized to 0.
int
[][] matrix =
new
int
[
5
][
5
];
A.
True
B.
False
8.5
How many elements are array matrix (int[][] matrix = new int[5][5])?
A.
14
B.
20
C.
25
D.
30
8.6
Analyze the following code:
public
class
Test {
public
static
void
main(String[] args) {
boolean
[][] x =
new
boolean
[
3
][];
x[
0
] =
new
boolean
[
1
]; x[
1
] =
new
boolean
[
2
];
x[
2
] =
new
boolean
[
3
];
System.out.println(
"x[
2
][
2
] is "
+ x[
2
][
2
]);
}
}
A.
The program has a compile error because new boolean[3][] is wrong.
B.
The program has a runtime error because x[2][2] is null.
C.
The program runs and displays x[2][2] is null.
D.
The program runs and displays x[2][2] is true.
E.
The program runs and displays x[2][2] is false.
8.7
Assume int[][] x = {{1, 2}, {3, 4}, {5, 6}}, what are x.length are x[0].length?
A.
2 and 1
B.
2 and 2
C.
3 and 2
D.
2 and 3
E.
3 and 3
8.8
Assume int[][] x = {{1, 2}, {3, 4, 5}, {5, 6, 5, 9}}, what are x[0].length, x[1].length, and x[2].length?
A.
2, 3, and 3
B.
2, 3, and 4
C.
3, 3, and 3
D.
3, 3, and 4
E.
2, 2, and 2
Section 8.3 Processing Two-Dimensional Arrays
8.9
What is the output of the following program?
public
class
Test {
public
static
void
main(String[] args) {
int
[][] values = {{
3
,
4
,
5
,
1
}, {
33
,
6
,
1
,
2
}};
int
v = values[
0
][
0
];
for
(
int
row =
0
; row < values.length; row++)
for
(
int
column =
0
; column < values[row].length; column++)
if
(v < values[row][column])
v = values[row][column];
System.out.print(v);
}
}
A.
1
B.
3
C.
5
D.
6
E.
33
8.10
What is the output of the following program?
public
class
Test {
public
static
void
main(String[] args) {
int
[][] values = {{
3
,
4
,
5
,
1
}, {
33
,
6
,
1
,
2
}};
int
v = values[
0
][
0
];
for
(
int
[] list : values)
for
(
int
element : list)
if
(v > element)
v = element;
System.out.print(v);
}
}
A.
1
B.
3
C.
5
D.
6
E.
33
8.11
What is the output of the following program?
public
class
Test {
public
static
void
main(String[] args) {
int
[][] values = {{
3
,
4
,
5
,
1
}, {
33
,
6
,
1
,
2
}};
for
(
int
row =
0
; row < values.length; row++) {
java.util.Arrays.sort(values[row]);
for
(
int
column =
0
; column < values[row].length; column++)
System.out.print(values[row][column] +
" "
);
System.out.println();
}
}
}
A.
The program prints two rows 3 4 5 1 followed by 33 6 1 2
B.
The program prints on row 3 4 5 1 33 6 1 2
C.
The program prints two rows 3 4 5 1 followed by 2 1 6 33
D.
The program prints two rows 1 3 4 5 followed by 1 2 6 33
E.
The program prints one row 1 3 4 5 1 2 6 33
8.12
What is the output of the following code?
public
class
Test {
public
static
void
main(String[] args) {
int
[][] matrix =
{{
1
,
2
,
3
,
4
},
{
4
,
5
,
6
,
7
},
{
8
,
9
,
10
,
11
},
{
12
,
13
,
14
,
15
}};
for
(
int
i =
0
; i <
4
; i++)
System.out.print(matrix[i][
1
] +
" "
);
}
}
A.
1 2 3 4
B.
4 5 6 7
C.
1 3 8 12
D.
2 5 9 13
E.
3 6 10 14
8.13
What is the output of the following code?
public
class
Test5 {
public
static
void
main(String[] args) {
int
[][] matrix =
{{
1
,
2
,
3
,
4
},
{
4
,
5
,
6
,
7
},
{
8
,
9
,
10
,
11
},
{
12
,
13
,
14
,
15
}};
for
(
int
i =
0
; i <
4
; i++)
System.out.print(matrix[
1
][i] +
" "
);
}
}
A.
1 2 3 4
B.
4 5 6 7
C.
1 3 8 12
D.
2 5 9 13
E.
3 6 10 14
Section 8.4 Passing Two-Dimensional Arrays to Methods
8.14
Suppose a method p has the following heading:
public
static
int
[][] p()
What
return
statement may be used in p()?
A.
return 1;
B.
return {1, 2, 3};
C.
return int[]{1, 2, 3};
D.
return new int[]{1, 2, 3};
E.
return new int[][]{{1, 2, 3}, {2, 4, 5}};
8.15
What is the output of the following program?
public
class
Test {
public
static
void
main(String[] args) {
int
[][] values = {{
3
,
4
,
5
,
1
}, {
33
,
6
,
1
,
2
}};
for
(
int
row =
0
; row < values.length; row++) {
System.out.print(m(values[row]) +
" "
);
}
}
public
static
int
m(
int
[] list) {
int
v = list[
0
];
for
(
int
i =
1
; i < list.length; i++)
if
(v < list[i])
v = list[i];
return
v;
}
}
A.
3 33
B.
1 1
C.
5 6
D.
5 33
E.
33 5
Section 8.8 Multidimensional Arrays
8.16
Assume double[][][] x = new double[4][5][6], what are x.length, x[2].length, and x[0][0].length?
A.
4, 5, and 6
B.
6, 5, and 4
C.
5, 5, and 5
D.
4, 5, and 4
8.17
Which of the following statements are correct?
A.
char[][][] charArray = new char[2][2][];
B.
char[2][2][] charArray = {'a', 'b'};
C.
char[][][] charArray = {{'a', 'b'}, {'c', 'd'}, {'e', 'f'}};
D.
char[][][] charArray = {{{'a', 'b'}, {'c', 'd'}, {'e', 'f'}}};
8.18
What is the output of the following code?
public
class
Test {
public
static
void
main(String[] args) {
int
[][][] data = {{{
1
,
2
}, {
3
,
4
}},
{{
5
,
6
}, {
7
,
8
}}};
System.out.print(data[
1
][
0
][
0
]);
}
}
A.
1
B.
2
C.
4
D.
5
E.
6
8.19
What is the output of the following code?
public
class
Test {
public
static
void
main(String[] args) {
int
[][][] data = {{{
1
,
2
}, {
3
,
4
}},
{{
5
,
6
}, {
7
,
8
}}};
System.out.print(ttt(data[
0
]));
}
public
static
int
ttt(
int
[][] m) {
int
v = m[
0
][
0
];
for
(
int
i =
0
; i < m.length; i++)
for
(
int
j =
0
; j < m[i].length; j++)
if
(v < m[i][j])
v = m[i][j];
return
v;
}
}
A.
1
B.
2
C.
4
D.
5
E.
6