Collections Framework – Multiple Choice Questions (MCQs)

1. 25. How do you sort a `List` of objects using the natural ordering?

   • A. Using the `sort()` method of the `List` interface
   • B. Using `Collections.sort()` with the `List`
   • C. Using `Arrays.sort()` with the `List`
   • D. Using a for loop to manually sort

2. 26. How do you sort a `List` of objects using a custom `Comparator`?

   • A. Using the `sort()` method of the `List` interface with the `Comparator`
   • B. Using `Collections.sort()` with the `List` and the `Comparator`
   • C. Using `Arrays.sort()` with the `List` and the `Comparator`
   • D. Using a for loop with custom comparison

3. 27. Which class provides static methods for operating on collections?

   • A. Arrays
   • B. Collections
   • C. Objects
   • D. List

4. 28. What is the purpose of the `Collections.sort()` method?

   • A. To reverse the order of elements in a collection
   • B. To shuffle the elements in a collection
   • C. To sort the elements in a collection
   • D. To search for an element in a collection

5. 29. What is the purpose of the `Collections.shuffle()` method?

   • A. To sort the elements in a collection
   • B. To reverse the order of elements in a collection
   • C. To randomly permute the elements in a collection
   • D. To find the minimum element in a collection

6. 30. What is the purpose of the `Collections.reverse()` method?

   • A. To sort the elements in a collection
   • B. To reverse the order of elements in a collection
   • C. To shuffle the elements in a collection
   • D. To find the maximum element in a collection

7. 31. What is the purpose of the `Collections.binarySearch()` method?

   • A. To find the index of a specific element in a sorted list
   • B. To sort the elements in a list
   • C. To reverse the order of elements in a list
   • D. To shuffle the elements in a list

8. 32. What is the time complexity of accessing an element by index in an `ArrayList`?

   • A. O(1)
   • B. O(n)
   • C. O(log n)
   • D. O(n log n)

9. 33. What is the time complexity of accessing an element by index in a `LinkedList`?

   • A. O(1)
   • B. O(n)
   • C. O(log n)
   • D. O(n log n)

10. 34. What is the average time complexity of searching for an element in a `HashSet`?

    • A. O(1)
    • B. O(n)
    • C. O(log n)
    • D. O(n log n)

11. 35. What is the average time complexity of searching for an element in a `TreeSet`?

    • A. O(1)
    • B. O(n)
    • C. O(log n)
    • D. O(n log n)

12. 36. What is the average time complexity of getting a value by key in a `HashMap`?

    • A. O(1)
    • B. O(n)
    • C. O(log n)
    • D. O(n log n)