Practice Wildcards In Generics (6.6) - Generics and Type Inference - Advance Programming In Java

Practice: Wildcards in Generics

Lesson 6.6Generics and Type Inference

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9 questions

Flashcard drill
3 cards from this section. Quick, good the night before a test.
Exercise
6 questions · about 4 min · pass mark 70%. Hints available.
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Quiz
3 questions · about 2 min · pass mark 70%. Hints available.
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6 sample questions

Question 1.
What is an unbounded wildcard?
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Think about generic lists.
Question 2.
Write a method that accepts any list using an unbounded wildcard.
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Consider how to indicate no type restriction.
3Question 3.
What is the purpose of an unbounded wildcard in Java?
- To limit types to a specific class
- To accept any type
- To restrict types to a lower level
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Consider the flexibility allowed without specific criteria.
4Question 4.
True or False: Lower bounded wildcards allow the specified type and its subclasses.
- True
- False
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Reflect on the generalization vs. specialization.
Question 5.
Write a generic method using an upper bounded wildcard that takes a list of Animals and returns the count of Dogs in it.
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Consider type-checking when counting objects.
Question 6.
Create a method to add objects of any superclass type to a list of Integer, including handling exceptions if added wrongly.
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Think carefully about what type checks you need to ensure insertions are type-safe.

5 more questions in this section. Enroll free to practise them all.