Practice Generics and Wildcards in Collections - 4.5 | 4. Java Collections Framework (Advanced | Advance Programming In Java
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Generics and Wildcards in Collections

4.5 - Generics and Wildcards in Collections

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Learning

Practice Questions

Test your understanding with targeted questions

Question 1 Easy

What does a bounded wildcard in Java signify?

💡 Hint: Think about the terms 'extends' and 'super'.

Question 2 Easy

Explain how type erasure impacts generics in Java.

💡 Hint: Consider what happens during the compilation of generic code.

4 more questions available

Interactive Quizzes

Quick quizzes to reinforce your learning

Question 1

What does the wildcard List<? extends Number> indicate?

It allows any Number type
It only allows Integer type
It restricts to superclasses of Number

💡 Hint: Think about the meaning of 'extends'.

Question 2

True or False: Type erasure keeps all type parameters intact in compiled Java code.

True
False

💡 Hint: Consider what happens in older Java versions.

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Challenge Problems

Push your limits with advanced challenges

Challenge 1 Hard

Explain a scenario where using bounded wildcards can prevent potential runtime errors. Provide code samples for clarity.

💡 Hint: Consider data integrity in statistical applications.

Challenge 2 Hard

Develop a method utilizing lower bounded wildcards that allows adding different shapes to a list. Explain the significance of this approach.

💡 Hint: Think about object-oriented programming and polymorphism.

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Reference links

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