Which of the following correctly defines a functional interface that, given an object, returns the value of a Coin?
A)(Object obj) = ((Coin) obj).getValue()
B)(Object obj) - (Coin) obj.getValue()
C)(Object obj) = (Coin) obj.getValue()
D)(Object obj) - ((Coin) obj).getValue()

Question

Which of the following correctly defines a functional interface that, given an object, returns the value of a Coin?
A)(Object obj) => ((Coin) obj).getValue()
B)(Object obj) -> (Coin) obj.getValue()
C)(Object obj) => (Coin) obj.getValue()
D)(Object obj) -> ((Coin) obj).getValue()

Quizplus · Accepted Answer

Option D is correct because it uses the correct lambda expression syntax for Java, which is parameter -> expression. It casts the object to type Coin and then calls the getValue() method on it.

Which of the Following Correctly Defines a Functional Interface That