Question 10.05 pts

All the elements of an array in Java MUST conform to the same data type.

True

False

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Question 20.05 pts

What is the value stored in the variable z by the statements below? int[ ] q = {3, 2, -2, 4, 7, 0, 1}; int z = q.length;

1

3

6

7

None of the above

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Question 30.05 pts

Which of the following statements declares a new array variable with no syntax errors?

int[ ] myArr;

int[ ][ ] myArr;

int[ ] myArr = new int[ 12 ];

int[ ] myArr = { 3, 4, 5, 6 };

All of the above

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Question 40.05 pts

What is printed by the following code? int[ ] x = {3, 4, 5, 6, 7}; int[ ] y = x; for (int i = 0; i < 3; i++)

y[i + 2] = 3 * y[i];

System.out.println( x[3] );

5

6

9

12

15

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Question 50.05 pts

In the following method call, which argument is an array? myObject.some_method(x, y, 3);

x is an array

y is an array

both x and y are arrays

neither x nor y is an array

can't say without seeing more code

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Question 60.05 pts

Which of the following statements correctly uses a reference to the entire array myArray as the argument of the method call? (The method call comes from within the same class, so no qualifier is needed.) public void myMethod( int[ ] a ) { ... }

myMethod( myArray );

myMethod( myArray[ ] );

myMethod( myArray[ 0 ] );

All of the above

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Question 70.05 pts

An array of doubles is stored in the variable v as shown below. Which statement below will print some or all of the contents of the array with NO errors (syntax or logical)? int vSize = 5; double[ ] v = new double[vSize]; for (int i = 0; i < vSize; i++)

v[i] = 1.1;

System.out.println( v );

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

System.out.println( v[vSize] );

All of the above

None of the above

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Question 80.05 pts

Which of the following method signatures correctly specifies an array as a return type?

private array testMethod ( int x )

private int[ ] testMethod ( int x )

private double[5] testMethod ( int x )

private double testMethod[ ] ( int x )

can't tell from this code

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Question 90.05 pts

Which of the following is the BEST description of a 2-D array in Java?

a 2-D array is a table

a 2-D array is an array of arrays

a 2-D array is a matrix

a 2-D array is a nested loop

a 2-D array is an ArrayList

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Question 100.05 pts

A loop is being used to find the lowest value in a double array named numbers. Which of the following statements performs a useful initialization of the accumulator?

double lowestValue = 0;

double lowestValue = numbers;

double lowestValue = numbers[0];

double lowestValue; // no initialization needed

Any of the above.

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Question 110.05 pts

The following bit of code is attempting to find the sum of all the elements in the array 'codes'. One line contains a logic error. Which line is it? long[] codes = ...; // Assume the array has been filled with values ... long sum = 0; // line 1 for ( int i = 1; i < codes.length; i++ ) { // line 2

sum = sum + codes[i]; // line 3

}

line 1

line 2

line 3

Question 120.05 pts

Which of the following is true about a sifting operation?

The operation may produce more than one result.

The operation may produce no results.

The search must continue even after a match is found; the entire collection must be examined.

All of the above.

None of the above.

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Question 130.05 pts

The following bit of code is attempting to find the average number of characters in all of the Strings in a String array. One line has a syntax error. Which line is it? String[] names = ... // Assume the array has been filled with values ... double averageLength = 0; // line 1 int i; for (i = 0; i < names.length(); i++ ) { // line 2

averageLength += names[i].length(); // line 3

} averageLength = averageLength / i; // line 4

line 1

line 2

line 3

line 4

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Question 140.05 pts

The following bit of code is attempting to find the x-coordinate of the Point that is farthest to the right in the x-y plane in the array 'points'. One line contains an error. Which line is it? Point[] points = ... // Assume the array has been filled with Point object references ... double xMax = points[0].getX(); // line 1 for ( int i = 1; i < points.length; i++ ) { // line 2

if ( points[i].getX() > xMax ) { // line 3

xMax = points[i]; // line 4

}

}

line 2

line 3

line 4

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Question 150.05 pts

The last 3 lines in the following program are supposed to swap the two elements in the array 'blooms' identified by the index values 'mary' and 'john'. Choose from among the answers listed the correct statement for the middle of these 3 lines: Flower[] blooms = ... // Assume this array is filled with object references int mary, john; // Assume these variables have values assigned to them ... Flower temp = blooms[mary]; // What statement goes here?? blooms[john] = temp;

john = mary;

temp = blooms[john];

blooms[mary] = blooms[john];

blooms[john] = blooms[mary];

None of the above -- no statement is needed.

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Question 160.05 pts

The following statement constructs a new String array. What initial value is stored in each of the array elements? String[] words = new String[8];

the empty String ( "" )

the numbers 1 through 8

the numbers 0 through 7

the value null

the value void

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Question 170.05 pts

What is printed out by the following short program? double[] x1 = {3.3, 4.4, 5.5, 6.6}; double[] x2 = x1; x2[1] = 24.0; double x = x1[1] * 2; System.out.println(x1[1]);

3.3

4.4

6.6

8.8

24.0

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Question 180.05 pts

Consider this code: String[] names = {"Mary", "Jose", "Minh"}; System.out.println(names[1]); What is the data type of names[1]?

String

String[]

array

char

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Question 190.05 pts

[This is different than the previous question.] Consider this code: String[] names = {"Mary", "Jose", "Minh"}; System.out.println(names[1]); What is the data type of names?

String

String[]

array

char

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Question 200.05 pts

What will be printed by the following program? int[] nums1 = {7, 6, 5, 4}; int[] nums2 = {7, 6, 5, 4}; boolean ans1 = (nums1 == nums2); boolean ans2 = nums1.equals(nums2); boolean ans3 = Arrays.equals(nums1, nums2); System.out.println( ans1 + "-" + ans2 + "-" + ans3 );

true - true - true

false - true - true

false - false - true

false - false - false