unit 8 csa test
Consider the following data field and method. private int[][] mat; public void mystery () { for (int row = 1; row < mat.length; row++) { for (int col = 0; col < mat[0].length; col++) { if (row != col) mat[row][col] = mat[row - 1][col]; } } } Assume that mat contains the following values. Note that mat[0][4] is 2. 4 1 3 4 21 8 7 5 37 4 6 9 23 8 1 2 45 6 7 0 3 What values does mat contain after a call to mystery? A 4 1 3 4 2 4 8 3 4 2 4 8 6 4 2 4 8 6 2 2 4 8 6 2 3 B 4 1 3 4 2 4 1 3 4 2 4 1 3 4 2 4 1 3 4 2 4 1 3 4 2 C 4 1 3 4 2 4 1 3 4 2 1 8 7 5 3 7 4 6 9 2 3 8 1 2 4 D 4 4 4 4 4 1 1 1 1 1 7 7 7 7 7 3 3 3 3 3 5 5 5 5 5 E 4 8 6 2 3 4 8 6 2 3 4 8 6 2 3 4 8 6 2 3 4 8 6 2 3
4 1 3 4 2 4 8 3 4 2 4 8 6 4 2 4 8 6 2 2 4 8 6 2 3
Consider the following code segment. int[][] arr = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}}; int sum = 0; for (int[] x : arr) { for (int y = 0; y < x.length - 1; y++) { sum += x[y]; } } What is the value of sum as a result of executing the code segment? A 36 B 54 C 63 D 68 E 78
54
Consider the following code segment. int[][] arr = {{6, 2, 5, 7}, {7, 6, 1, 2}}; for (int j = 0; j < arr.length; j++) { for (int k = 0; k < arr[0].length; k++) { if (arr[j][k] > j + k) { System.out.println("!"); } } } How many times will "!" be printed when the code segment is executed? A 0 times B 2 times C 4 times D 6 times E 8 times
6 times
Consider the following code segment. What is printed as a result of executing the code segment? A 3 B 4 C 5 D 7 E 8
7
Consider the following code segment. int[] oldArray = {1, 2, 3, 4, 5, 6, 7, 8, 9}; int[][] newArray = new int[3][3]; int row = 0; int col = 0; for (int index = 0; index < oldArray.length; index++) { newArray[row][col] = oldArray[index]; row++; if ((row % 3) == 0) { col++; row = 0; } } System.out.println(newArray[0][2]); What is printed as a result of executing the code segment? A 3 B 4 C 5 D 7 E 8
7
Consider the following code segment, where num is an integer variable. int[][] arr = {{11, 13, 14 ,15}, {12, 18, 17, 26}, {13, 21, 26, 29}, {14, 17, 22, 28}}; for (int j = 0; j < arr.length; j++) { for (int k = 0; k < arr[0].length; k++) { if (arr[j][k] == num) { System.out.print(j + k + arr[j][k] + " "); } } } What is printed when num has the value 14 ? A 14 14 B 16 17 C 17 16 D 18 19 E 19 18
16 17
Consider the following code segment. int[][] array2D = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}, {13, 14, 15, 16}}; for (int[] i : array2D) { for (int x : i) { System.out.print(x + " "); } System.out.println(" "); } How many times will the statement System.out.print(x + " ") be executed? A 3 times B 4 times C 6 times D 12 times E 16 times
16 times
Consider the following code segment. int[][] arr = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}, {3, 2, 1}}; for (int j = 0; j < arr.length; j++) { for (int k = j; k < arr[0].length; k++) { System.out.print(arr[j][k] + " "); } System.out.println(); } What output is printed when the code segment is executed? A 2 3 6 B 1 2 3 4 5 7 C 1 2 3 5 6 9 D 1 4 7 5 8 9 E 1 2 3 5 6 9 1
1 2 3 5 6 9
Consider the following Util class, which contains two methods. The completed sum1D method returns the sum of all the elements of the 1-dimensional array a. The incomplete sum2D method is intended to return the sum of all the elements of the 2-dimensional array m. Assume that sum1D works correctly. Which of the following can replace / * missing code * / so that the sum2D method works correctly? A I only B II only C I and II only D II and III only E I, II, and III
I, II, and III
Consider the following code segment, which is intended to declare and initialize the two-dimensional (2D) String array things. /* missing code */ = {{"spices", "garlic", "onion", "pepper"}, {"clothing", "hat", "scarf", "gloves"}, {"plants", "tree", "bush", "flower"}, {"vehicles", "car", "boat", "airplane"}}; Which of the following could replace /* missing code */ so that things is properly declared? A new String[][] things B new(String[][]) things C String[] String[] things D String[][] things E [][]String things
String[][] things
Assume mat is defined as follows. int dim = 4; int[][] mat = new int[dim][dim]; Consider the following code segment. int sum = 0; for (int row = 0; row < dim; row++) { sum = sum + mat[row][dim - 1]; } Assume that mat contains the following values before the code segment is executed. Note that mat[0][3] is 2. 012301122112242132631428 What value will sum contain after the code segment is executed? A 6 B 8 C 13 D 15 E 20
20
Consider the following code segment. int[][] values = {{1, 2, 3}, {4, 5, 6}}; int x = 0; for (int j = 0; j < values.length; j++) { for (int k = 0; k < values[0].length; k++) { if (k == 0) { values[j][k] *= 2; } x += values[j][k]; } } What is the value of x after the code segment is executed? A 7 B 17 C 21 D 26 E 27
26
Consider the following two-dimensional array definition. int[][] data = new int[5][10]; Consider the following code segment, where all elements in data have been initialized. for (int j = 0; j < data.length; j++) { for (int k = 0; k < data[0].length; k++) { if (j == k) { System.out.println(data[j][k]); } } } How many times is the println method called when the code segment is executed? A 4 B 5 C 9 D 10 E 15
5
Consider the following code segment. String[][] letters = {{"A", "B", "C", "D"}, {"E", "F", "G", "H"}, {"I", "J", "K", "L"}}; for (int col = 1; col < letters[0].length; col++) { for (int row = 1; row < letters.length; row++) { System.out.print(letters[row][col] + " "); } System.out.println(); } What is printed as a result of executing this code segment? A A E I F J K B B F J C G K D H L C E I F J G K H L D F G H J K L E F J G K H L
F J G K H L
Consider the following code segment. String[][] arr = {{"Hello,", "Hi,", "Hey,"}, {"it's", "it is", "it really is"}, {"nice", "great", "a pleasure"}, {"to", "to get to", "to finally"}, {"meet", "see", "catch up with"}, {"you", "you again", "you all"}}; for (int j = 0; j < arr.length; j++) { for (int k = 0; k < arr[0].length; k++) { if (k == 1) { System.out.print(arr[j][k] + " "); } } } What, if anything, is printed when the code segment is executed? A Nothing is printed due to an ArrayIndexOutOfBoundsException. B Hello, it's nice to meet you C Hey, it really is a pleasure to finally catch up with you all D Hi, it is great to get to see you again E it's it is it really is
Hi, it is great to get to see you again
Assume that a two-dimensional (2D) array arr of String objects with 3 rows and 4 columns has been properly declared and initialized. Which of the following can be used to print the elements in the four corner elements of arr ? A System.out.print(arr[0, 0] + arr[0, 3] + arr[2, 0] + arr[2, 3]); B System.out.print(arr[1, 1] + arr[1, 4] + arr[3, 1] + arr[3, 4]); C System.out.print(arr[0][0] + arr[0][2] + arr[3][0] + arr[3][2]); D System.out.print(arr[0][0] + arr[0][3] + arr[2][0] + arr[2][3]); E System.out.print(arr[1][1] + arr[1][4] + arr[3][1] + arr[3][4]);
System.out.print(arr[0][0] + arr[0][3] + arr[2][0] + arr[2][3]);
Consider the following method. Which of the following best describes what is returned by the calculate method? A The largest value in the two-dimensional array B The smallest value in the two-dimensional array C The row index of an element with the largest value in the two-dimensional array D The row index of an element with the smallest value in the two-dimensional array E The column index of an element with the largest value in the two-dimensional array
The column index of an element with the largest value in the two-dimensional array
A two-dimensional array arr is to be created with the following contents. boolean[][] arr = {{false, true, false}, {false, false, true}}; Which of the following code segments can be used to correctly create and initialize arr ? A boolean arr[][] = new boolean[2][3]; arr[0][1] = true; arr[1][2] = true; B boolean arr[][] = new boolean[2][3]; arr[1][2] = true; arr[2][3] = true; C boolean arr[][] = new boolean[3][2]; arr[0][1] = true; arr[1][2] = true; D boolean arr[][] = new boolean[3][2]; arr[1][0] = true; arr[2][1] = true; E boolean arr[][] = new boolean[3][2]; arr[2][1] = true; arr[3][2] = true;
boolean arr[][] = new boolean[2][3]; arr[0][1] = true; arr[1][2] = true;
Consider the following method. public boolean checkIndexes(double[][] data, int row, int col) { int numRows = data.length; if (row < numRows) { int numCols = data[0].length; return col < numCols; } else { return false; } } Consider the following variable declaration and initialization, which appears in a method in the same class as checkIndexes. double[][] table = new double[5][6]; Which of the following method calls returns a value of true ? A checkIndexes(table, 4, 5) B checkIndexes(table, 4, 6) C checkIndexes(table, 5, 4) D checkIndexes(table, 5, 6) E checkIndexes(table, 6, 5)
checkIndexes(table, 4, 5)
Consider the following method, which is intended to print the values in its two-dimensional integer array parameter in row-major order. public static void rowMajor(int[][] arr) { /* missing code */ } As an example, consider the following code segment. int[][] theArray = {{1, 2}, {3, 4}, {5, 6}, {7, 8}}; rowMajor(theArray); When executed, the code segment should produce the following output. 1 2 3 4 5 6 7 8 Which of the following code segments can replace /* missing code */ so that the rowMajor method works as intended? A for (int j : arr){ for (int k : j) { System.out.print(j + " "); }} B for (int j : arr){ for (int k : j) { System.out.print(k + " "); }} C for (int[] j : arr){ for (int k : j) { System.out.print(j + " "); }} D for (int[] j : arr){ for (int k : j) { System.out.print(k + " "); }} E for (int[] j : arr){ for (int k : j) { System.out.print(arr[k] + " "); }}
for (int[] j : arr){ for (int k : j) { System.out.print(k + " "); }}
Consider the following code segment, where nums is a two-dimensional (2D) array of integers. The code segment is intended to print "test1234". System.out.print("test" + nums[0][0] + nums[1][0] + nums[1][1] + nums[0][1]); Which of the following code segments properly declares and initializes nums so that the code segment works as intended? A int[][] nums = {{1, 2}, {3, 4}}; B int[][] nums = {{1, 2}, {4, 3}}; C int[][] nums = {{1, 3}, {2, 4}}; D int[][] nums = {{1, 4}, {2, 3}}; E int[][] nums = {{1, 4}, {3, 2}};
int[][] nums = {{1, 4}, {2, 3}};
Consider the following code segment, where num is a properly declared and initialized integer variable. The code segment is intended to traverse a two-dimensional (2D) array arr looking for a value equal to num and then print the value. The code segment does not work as intended. int[][] arr = {{7, 3, 6, 4}, {9, 2, 0, 5}, {1, 4, 3, 8}}; for (int j = 0; j < arr.length - 1; j++) { for (int k = 0; k < arr[0].length; k++) { if (arr[j][k] == num) { System.out.println(arr[j][k]); } } } For which of the following values of num does the code segment not work as intended? A num = 5 B num = 6 C num = 7 D num = 8 E num = 9
num = 8
Consider the following code segment, where letters is a two-dimensional (2D) array that contains possible letters. The code segment is intended to print "DIG". String[][] letters = {{"A", "B", "C"}, {"D", "E", "F"}, {"G", "H", "I"}}; System.out.println( /* missing code */ ); Which of the following could replace /* missing code */ so that the code segment works as intended? A letters[2][1] + letters[3][3] + letters[3][1] B letters[2][0] + letters[2][2] + letters[1][0] C letters[1][2] + letters[3][3] + letters[1][3] D letters[1][0] + letters[2][2] + letters[2][0] E letters[0][1] + letters[2][2] + letters[0][2]
letters[1][0] + letters[2][2] + letters[2][0]
Consider the following method. The following code segment appears in another method in the same class. Which of the following represents the contents of arr as a result of executing the code segment?
{1, 6, 3, 4}
Consider the following method, which is intended to return true if 0 is found in its two-dimensional array parameter arr and false otherwise. The method does not work as intended. public boolean findZero(int[][] arr) { for (int row = 0; row <= arr.length; row++) { for (int col = 0; col < arr[0].length; col++) { if (arr[row][col] == 0) { return true; } } } return false; } Which of the following values of arr could be used to show that the method does not work as intended? A {{30, 20}, {10, 0}} B {{4, 3}, {2, 1}, {0, -1}} C {{0, 1, 2}, {3, 4, 5}, {6, 7, 8}} D {{5, 10, 15, 20}, {25, 30, 35, 40}} E {{10, 20, 0, 30, 40}, {60, 0, 70, 80, 90}}
{{5, 10, 15, 20}, {25, 30, 35, 40}}
Consider the following code segment. int[][] points = {{11, 12, 13, 14, 15}, {21, 22, 23, 24, 25}, {31, 32, 33, 34, 35}, {41, 42, 43, 44, 45}}; for (int row = 0; row < points.length; row++) { for (int col = points[0].length - 1; col >= row; col--) { System.out.print(points[row][col] + " "); } System.out.println(); } What is printed when this code segment is executed? A 15 14 25 24 23 35 34 33 32 45 44 43 42 41 B 15 14 13 12 25 24 23 35 34 45 C 11 12 13 14 15 21 22 23 24 31 32 33 41 42 D 15 14 13 12 11 25 24 23 22 35 34 33 45 44 E 15 14 13 12 11 25 24 23 22 21 35 34 33 32 31 45 44 43 42 41
15 14 13 12 11 25 24 23 22 35 34 33 45 44
