Mastering Java: The Ultimate Quiz for 'Thinking in Java'

What does ArrayList allow you to do with elements?

1. Look up an object using a number

2. Insert duplicates without any restriction

3. Only store elements of the same type without generics

4. Execute methods specific to ArrayList only

The correct answer is: Look up an object using a number

An ArrayList allows you to look up an object using its index number. Option B is incorrect because each element in an ArrayList must be unique. Option C is incorrect because you can specify the data type of the elements in an ArrayList using generics, allowing for different types of elements to be stored. Option D is also incorrect because although ArrayList has its own methods, it can also use methods from the List interface.