Unit 6 - Arrays Review

 Which of the following statements about Java arrays is false?

• Arrays can hold primitive data types and objects

• The size of an array can be changed after initialization

• Multi-dimensional arrays are arrays of arrays

• Array elements are stored in contiguous memory locations

Which of the following is NOT a valid way to declare and initialize an array in Java?

• nt[] numbers = new int[5];

• int numbers[] = {1, 2, 3, 4, 5};

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

•  int numbers[5] = {1, 2, 3, 4, 5};

Consider the following code snippet:

   int[] arr = new int[5];

   arr[5] = 10;

   What will happen when this code is executed?

• The value 10 will be stored at index 5

• An ArrayIndexOutOfBoundsException will be thrown

• The array will automatically resize to accommodate the new element

• The value 10 will be stored at index 4

Which of the following best describes the relationship between an array's reference variable and its object in memory?

• They are stored in the same memory location

• The reference variable stores the first element of the array

• The reference variable points to the array object on the heap

• The reference variable stores the length of the array

What is the output of the following code?

 int[] a = {1, 2, 3, 4, 5};

    int[] b = a;

    b[2] = 10;

    System.out.println(a[2]);

• 3

• 10

• 5

• An error occurs

In the example, is it possible to use an enhanced for loop instead of a for loop?

• True

• False

Consider the following code:

   int[] arr = {1, 2, 3, 4, 5};

   for(int i = 0; i < arr.length; i += 2) {

       System.out.print(arr[i] + " ");

   }

   What will be the output?

• 1 2 3 4 5

•  1 3 5

• 2 4

• 1 3

What is the primary advantage of using a for-each loop over a traditional for loop when traversing an array?

• It's faster in terms of execution time

• It allows modification of array elements

• It's less prone to off-by-one errors

• It can access the array in reverse order

Which of the following is true about the memory allocation of arrays in Java?

• Memory is always allocated on the stack

• Memory is always allocated on the heap

• Primitive arrays are on the stack, object arrays on the heap

• The programmer can choose between stack and heap allocation

In the context of array traversal, what is the main drawback of using a while loop compared to a for loop?

• While loops are slower

• While loops are more prone to infinite loops

• While loops can't access array elements by index

• While loops can't be used with the array's length property