PatternMatchingExample.java

static void printBookOld(Book book) {
        if (book instanceof Thriller) {
            Thriller thriller = (Thriller) book; // must-do explicit casting
            System.out.println(thriller.getSuspense());
        } else if (book instanceof AutoBiography) {
            AutoBiography biography = (AutoBiography) book; // must-do explicit casting
            System.out.println(biography.getContribution());
        }
    }

    static void printBookNew(Book book) {
        if (book instanceof Thriller thriller) {   /* casting in one-line */
            System.out.println(thriller.getSuspense());
        } else if (book instanceof AutoBiography biography) {   /* casting in one-line */
            System.out.println(biography.getContribution());
        }
    }