Practice Scope And Access (22.7) - Lambda Expressions and Functional Interfaces

Practice: Scope and Access

Lesson 22.7Lambda Expressions and Functional Interfaces

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8 questions

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6 sample questions

Question 1.
What does it mean for a variable to be effectively final?
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Think about how the variable is used in a lambda.
Question 2.
Can you use a variable that is modified after its declaration inside a lambda?
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Consider the definition of effectively final.
3Question 3.
What is an effectively final variable?
- A variable that can change after declaration
- A variable never modified after assignment
- Any declared variable
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Reflect on the term 'effectively'.
4Question 4.
Can a lambda modify local variables in its enclosing scope?
- True
- False
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Think about the rules that restrict what lambdas can access.
Question 5.
Create a Java program that uses a lambda to sum the values of an array while trying to modify a local counter inside the lambda. What errors arise?
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Check what happens to any counter variable if you try to redefine it in the lambda.
Question 6.
Illustrate with code how an effectively final variable can be used in a sorting lambda while clarifying why a non-final variable cannot be used.
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Experiment with creating two different versions of the same functionality.

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