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

What exception is thrown when attempting to get enum constants from a non-enum class?

1. UnsupportedOperationException

2. IllegalArgumentException

3. NullPointerException

4. ClassCastException

The correct answer is: NullPointerException

A NullPointerException is thrown when attempting to access a member of a non-initialized object. It is important to note that while all of the other exceptions listed may occur when working with enum constants or classes, a NullPointerException specifically relates to trying to retrieve a member of a non-initialized object. An UnsupportedOperationException can occur when an operation is not supported by the given collection, and is not directly related to enums or their constants. An IllegalArgumentException can occur when invalid arguments are provided to a method or constructor, which would not be the case when retrieving enum constants from a non-enum class. A ClassCastException can occur when trying to cast an object to a type that it is not compatible with, which may happen when working with enums and their associated classes, but is not specific to retrieving enum constants.