Java Arrays Quiz - Multiple Choice Questions And Answers

Q. How do you declare an array in Java?

A. int[] arrayName;
B. arrayName[] int;
C. int arrayName[];
D. int arrayName();
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Q. How do you access an element from an array in Java?

A. arrayName(elementIndex);
B. arrayName[index];
C. arrayName.index()
D. index.arrayName();
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Q. What is the length of an array in Java?

A. size()
B. length()
C. size
D. length
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Q. How do you initialize an array in Java?

A. int[] arrayName = new int[5];
B. arrayName = new int[5];
C. int arrayName() = new int[5];
D. int[] arrayName = {1, 2, 3, 4, 5};
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Q. Can the size of an array be changed after it is created?

A. Yes
B. No
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Q. How do you iterate through elements in an array in Java?

A. Using a for loop
B. Using a while loop
C. Using a do-while loop
D. All of the above
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Q. How do you find the maximum element in an array in Java?

A. Using a loop and comparison
B. Using the Math.max() method
C. Using the Collections.max() method
D. All of the above
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Q. How do you sort an array in ascending order in Java?

A. Using a loop and swapping
B. Using the Arrays.sort() method
C. Using the Collections.sort() method
D. All of the above
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Q. What is the purpose of the Predicate functional interface in Java 8?

A. To produce results
B. To consume values
C. To filter elements based on a condition
D. To transform values
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Q. How do you copy an array in Java?

A. Using a loop and assignment
B. Using the Arrays.copy() method
C. Using the System.arraycopy() method
D. All of the above
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Q. What is the correct way to declare and initialize a one-dimensional array of integers in Java?

A.

int[] numbers = {1, 2, 3, 4, 5};

B.

Integer[] numbers = {1, 2, 3, 4, 5};

C.

int numbers = {1, 2, 3, 4, 5};

D.

Integer numbers = new Integer[]{1, 2, 3, 4, 5};

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Q. What will be the output of the following code snippet?

int[] numbers = {1, 2, 3, 4, 5};

for (int i = 0; i < numbers.length; i++) {
    if (numbers[i] % 2 == 0) {
        System.out.println(numbers[i]);
    }
}

A.

2
4

B.

1
2
3
4
5

C.

2

D.

1
3
5

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Q. What is the output of the following code snippet?

int[] numbers = new int[5];

System.out.println(numbers[0]);

A.

0

B.

1

C.

null

D.

Error: ArrayIndexOutOfBoundsException

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Q. How do you access the third element in a one-dimensional array called numbers?

A.

numbers[0]

B.

numbers[2]

C.

numbers[3]

D.

numbers[1]

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Q. Which of the following is NOT a valid way to initialize a two-dimensional array in Java?

A.

int[][] matrix = new int[][]{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};

B.

int[][] matrix = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};

C.

int[][] matrix = new int[3][3];
matrix = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};

D.

int[][] matrix = {{1, 2, 3}, new int[]{4, 5, 6}, {7, 8, 9}};

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Q. What will be the output of the following code snippet?

int[][] matrix = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};

System.out.println(matrix[1][2]);

A.

3

B.

2

C.

5

D.

4

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Q. How do you declare a jagged array in Java?

A.

int[][] matrix = new int[3][];
matrix[0] = new int[2];
matrix[1] = new int[4];
matrix[2] = new int[3];

B.

int[][] matrix = new int[][3];
matrix[0] = new int[2];
matrix[1] = new int[4];
matrix[2] = new int[3];

C.

int[][] matrix = new int[][];
matrix[0] = new int[2];
matrix[1] = new int[4];
matrix[2] = new int[3];

D.

int[][] matrix = new int[3];
matrix[0] = new int[2];
matrix[1] = new int[4];
matrix[2] = new int[3];

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Q. What is the length of the following jagged array?

int[][] matrix = {
    {1, 2},
    {3, 4, 5},
    {6, 7, 8, 9}
};

System.out.println(matrix.length);

A.

1

B.

2

C.

3

D.

4

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Q. How do you loop through a two-dimensional array in Java using nested loops?

A.

for (int i = 0; i < array.length; i++) {
    for (int j = 0; j < array[0].length; j++) {
        System.out.println(array[i][j]);
    }
}

B.

for (int i = 0; i < array[0].length; i++) {
    for (int j = 0; j < array.length; j++) {
        System.out.println(array[i][j]);
    }
}

C.

for (int i = 0; i < array.length; i++) {
    for (int j = 0; j < array[i].length; j++) {
        System.out.println(array[i][j]);
    }
}

D.

for (int[] row : array) {
    for (int element : row) {
        System.out.println(element);
    }
}

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Q. What is the correct way to access an element in a three-dimensional array called matrix?

A.

matrix[0][0][0]

B.

matrix[0, 0, 0]

C.

matrix[0, 0][0]

D.

matrix[0][0][0]

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