Get ready for our blog post featuring a cool quiz on Java Enums. It’s a fantastic way to test your understanding of this useful Java feature!
Java Enums (short for enumeration) are a special Java type used to define collections of constants. More powerful than simple constants, enums provide a way to group related values and use them in a type-safe way. This makes your code more readable and eliminates errors caused by invalid values. Enums are great for creating fixed sets of constants, like days of the week, months, and more.
Jump into our MCQs to challenge your knowledge of Java Enums. Whether you’re a beginner or looking to refresh your skills, this quiz is a great opportunity to learn more about how enums can make your Java programs better. Ready to start? Let’s explore the world of Java Enums together!
1. Which of the following best describes an enum in Java?
Answer:
Explanation:
Enums are special classes in Java used to define collections of constants.
2. How do you define an enum that represents days of the week?
Answer:
Explanation:
Enums are defined using the enum keyword followed by the enum name and constants enclosed in curly braces.
3. Which method can be used to get the ordinal value of an enum constant?
Answer:
Explanation:
The ordinal() method of an enum returns the ordinal value (position) of the enum constant, starting from 0.
4. Can an enum have a constructor?
Answer:
Explanation:
Enums can have constructors, but they are always private. This is to prevent the creation of new enum instances.
5. Can you override the toString() method in an enum?
Answer:
Explanation:
Just like any other class in Java, you can override the toString() method in an enum to provide a custom string representation of the enum constant.
6. Which method can be used to get an enum constant by its string name?
Answer:
Explanation:
The static valueOf() method in the enum can be used to retrieve an enum constant by its string name.
7. Can enums extend other classes in Java?
Answer:
Explanation:
Enums cannot extend other classes in Java because they implicitly extend the java.lang.Enum class. However, they can implement interfaces.
8. What happens when you try to print an enum constant directly?
Answer:
Explanation:
The default toString() method in enums returns the name of the constant. So when you print an enum constant directly, it shows the constant’s name.
9. Can an enum be declared inside a class?
Answer:
Explanation:
An enum can be declared inside a class, and when it’s done this way, it’s implicitly static.
10. Which of the following statements about enums is NOT correct?
Answer:
Explanation:
Enums cannot be instantiated using the new keyword. The constants defined in an enum are the only instances that can exist for that enum type.
Enums provide a concise and type-safe way to represent a fixed set of related constants in Java. They are versatile and can be employed in a variety of use cases, from simple value collections to sophisticated type patterns. If you found this quiz informative, continue delving deeper into Java’s features and enhance your understanding. Happy coding!