Quiz 2.6: Questions with a name

Question 1 — The Decorator pattern

Which UML diagram belongs to the Decorator pattern?

1. A wrapper that adds behaviour around a component
2. A class that creates objects for a family of products
3. A class that has exactly one instance

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A wrapper that adds behaviour around a component

Explanation

The Decorator wraps a component and forwards calls to it, so behaviour can be added without subclassing.

Question 2 — Which pattern wraps a component?

Which pattern wraps a component?

1. Decorator
2. Singleton

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Decorator

Testing FizzBuzz

Given this class:

public class FizzBuzz {
    public String fizzbuzzer(int n) {
        return n % 15 == 0 ? "FizzBuzz" : String.valueOf(n);
    }
}

Subquestion 1a — Which test is useful? (2 points)

Which test is useful?

1. A test that asserts "FizzBuzz" for input 15
2. A test that only checks that the result is not null

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A test that asserts "FizzBuzz" for input 15

Subquestion 1b — What does fizzbuzzer(7) return? (1 point)

What does fizzbuzzer(7) return?

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7