Core Java · interview question

Given the following code, which method will be executed at runtime? class Product { void display() { System.out.println("Product"); } } class Book extends Product { void display() { System.out.println("Book"); } } public class Main { public static void main(String[] args) { Product p = new Book(); p.display(); } }?

Multiple choiceMediumchapter-5-curatedpremiumcore-javaupcasting-and-dynamic-dispatch

java

class Product { void display() { System.out.println("Product"); } }
class Book extends Product { void display() { System.out.println("Book"); } }
public class Main { public static void main(String[] args) { Product p = new Book(); p.display(); } }

No output due to compilation errorNo output due to runtime error"Product""Book"

Answer and explanation

Correct answer

D. "Book"

Why

The method executed is determined by the runtime type of the object. Since the object is instantiated as a Book, the Book's display method will be called, printing "Book".

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