APCSA unit 6

Which of the following arrays has a length of 5?

• double[] arr = new double[6];

• double[] arr = {3, 12, 52, 23, 14, 0};

• double[] arr = new double[]{3, 12, 52, 23, 14, 0};

• all of these

• none of these

Which of the following statements correctly initializes an array of integers with a size of 4?

• int[] arr = new int[4];

• int[] arr = {1, 2, 3};

• int[] arr = new int[]{1, 2, 3, 4, 5};

• none of these

Which option represents a correctly initialized string array containing exactly 3 elements?

• String[] arr = new String[2];

• String[] arr = {"Hello", "World", "!"};

• String[] arr = new String[]{"Java"};

• all of these

• none of these

How do you initialize a boolean array of size 5 with all elements set to true?

• boolean[] arr = new boolean[5];

• boolean[] arr = {true, true, true, true, true};

• boolean[] arr = new boolean[]{true};

• none of these

The following code is designed to return true if a target value is present in an array of integers.

Which of the following statements is true?

• The code will not work correctly because the loop will not access each of the numbers correctly.

• The code will not work correctly because it may return true too soon.

• The code will not work correctly because the method may return false too soon.

• 
  

  The code will work as intended.

What does the following code do when executed?

• It will produce an error because the conditional statement is not set up correctly.

• It will count the number of times the value in the highTemp array exceeds the target value.

• It will produce an ArrayIndexOutOfBoundsException

• It will count the number of times that the value in the array is greater than the previous value in the array.

Which of the following statements is valid? Assume that variable arr is an array of n integers and that the following is true:

arr[0] != arr[i] for all values of i from 1 through n - 1

• The element arr[0] does not occur anywhere else in the array

• arr has no duplicates

• arr has duplicates

• arr is sorted

• arr is not sorted

The following codes are intended to add 5 to each item in the array.

Which statement is true?

• Both I and II will correctly add 5 to the numbers array.

• 
  

  Neither I nor II will correctly add 5 to the numbers array.

• 
  

  I will correctly add 5 to the numbers array. II will not correctly add 5 to the numbers array.

• 
  

  II will correctly add 5 to the numbers array. I will not correctly add 5 to the numbers array.

• I will have an error. II will work correctly add 5 to the numbers array.

The following code is intended to shift all elements to the right by one space and wrap the last element around to the first element.

Which statement is true?

• The code will not work as intended. Line 5 should be changed to for (int i = 0; i < arr.length; i++)

• 
  

  The code will not work as intended. Line 5 should be changed to for (int i = arr.length; i > 0; i--)

• The code will not work as intended. Line 7 should be changed to arr[i-1] = arr[i];

• 
  

  The code will not work as intended. It will produce an ArrayIndexOutOfBoundsException.

• 
  

  The code will work as intended.

The following method is intended to return true if the array element value contains the same number in consecutive array elements.

Which of the following are needed to correct the code?

I. Change line 3 to: int i = 0;
II. Change line 4 to: while (i < nums.length - 1)
III. Swap lines 7 and 10

• I only

• II only

• III only

• Make both I and II changes

• make all changes