ArrayList get() method quiz: Test your Java indexing knowledge

📚 Quick Study Guide

• 🔑 The `get(int index)` method retrieves the element at the specified position in an `ArrayList`.
• 🔢 Indexing in Java `ArrayLists` starts at 0. So, the first element is at index 0, the second at index 1, and so on.
• 🚨 If you try to access an index that is out of bounds (i.e., less than 0 or greater than or equal to the size of the `ArrayList`), an `IndexOutOfBoundsException` will be thrown.
• 📏 The valid index range for an `ArrayList` of size `n` is from 0 to `n-1`.
• ⏱️ The `get()` method provides constant time complexity, O(1), for accessing elements.
• 💡 Always check the size of the `ArrayList` before calling `get()` to avoid exceptions.

🧪 Practice Quiz

1. What is the index of the first element in an `ArrayList`?

   1. -1
   2. 0
   3. 1
   4. The size of the `ArrayList`

2. What happens if you try to access an index that is out of bounds in an `ArrayList` using the `get()` method?

   1. It returns `null`.
   2. It returns a default value.
   3. It throws an `IndexOutOfBoundsException`.
   4. It resizes the `ArrayList`.

3. Given an `ArrayList` named `myList` with 5 elements, what is the valid range of indices you can access using the `get()` method?

   1. 0 to 5
   2. 1 to 5
   3. 0 to 4
   4. 1 to 4

4. What is the time complexity of the `get()` method in an `ArrayList`?

   1. O(n)
   2. O(log n)
   3. O(1)
   4. O(n^2)

5. How can you prevent an `IndexOutOfBoundsException` when using the `get()` method?

   1. Always access the last element.
   2. Always access the first element.
   3. Check the size of the `ArrayList` before accessing an element.
   4. Use a try-catch block without checking the size.

6. Consider an `ArrayList` called `numbers` containing the integers [10, 20, 30, 40, 50]. What will `numbers.get(2)` return?

   1. 10
   2. 20
   3. 30
   4. 40

7. If an `ArrayList` is empty, what happens when you call `get(0)`?

   1. Returns 0.
   2. Returns null.
   3. Throws an `IndexOutOfBoundsException`.
   4. Creates a new element at index 0.