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Practice Questions
Test your understanding with targeted questions related to the topic.
Question 1
Easy
What is the purpose of the Optional class in Java?
💡 Hint: Consider how you would check for null values.
Question 2
Easy
How do you create an Optional instance from a potentially null value?
💡 Hint: Remember the method name that indicates possible absence of value.
Practice 4 more questions and get performance evaluation
Interactive Quizzes
Engage in quick quizzes to reinforce what you've learned and check your comprehension.
Question 1
What does the Optional class help prevent in Java?
- IndexOutOfBoundsException
- NullPointerException
- IllegalArgumentException
💡 Hint: Recall the common exception types Java programs face.
Question 2
True or False: Optional can hold null values.
- True
- False
💡 Hint: Think about what Optional encapsulates.
Solve and get performance evaluation
Challenge Problems
Push your limits with challenges.
Question 1
Write a method using Optional to return an integer value from a collection of numbers, where the number is searched based on criteria (e.g., greater than 10).
💡 Hint: Use streams to filter and find the first matching value.
Question 2
Design an API method that returns a user based on username, using Optional in its return type.
💡 Hint: Consider how the absence of a user will be indicated.
Challenge and get performance evaluation