The answer is A because the code fragment uses the ZoneId and ZonedDateTime classes to create two date-time objects with the same local date-time but different zone offsets. The ZoneId class represents a time-zone ID, such as America/Chicago, and the ZonedDateTime class represents a date-time with a time-zone in the ISO-8601 calendar system. The code fragment creates two ZonedDateTime objects with the same local date-time of 2021-11-07T01:30, but different zone IDs of America/Chicago and UTC. The code fragment then compares the two objects using the equals and isEqual methods.

The equals method compares the state of two objects for equality. In this case, it compares the local date-time, zone offset, and zone ID of the two ZonedDateTime objects. Since the zone offsets and zone IDs are different, the equals method returns false.

The isEqual method compares the instant of two temporal objects for equality. In this case, it compares the instant of the two ZonedDateTime objects, which is derived from the local date-time and zone offset. Since DST in Chicago ended on November 7th at 2 AM in 2021, the local date-time of 2021-11-07T01:30 in America/Chicago corresponds to the same instant as 2021-11-07T06:30 in UTC. Therefore, the isEqual method returns true.

Hence, the output is true false.  References :

Oracle Certified Professional: Java SE 17 Developer

Java SE 17 Developer

OCP Oracle Certified Professional Java SE 17 Developer Study Guide

ZoneId (Java Platform SE 8 )

ZonedDateTime (Java Platform SE 8 )

Time Zone & Clock Changes in Chicago, Illinois, USA

Daylight Saving Time Changes 2023 in Chicago, USA

The code fragment is trying to sort a list of books using the Collections.sort() method. The correct answer is D, because the compareTo() method is not the correct way to compare two objects in a Comparator.  The compare() method is the correct way to compare two objects in a Comparator and return an int value that indicates their order 1 .  The compareTo() method is used to implement the Comparable interface, which defines the natural order of objects of a class 2 .  The other options are incorrect because they either do not change the type of the list, which is already mutable, or they do not use the correct syntax for sorting a stream, which requires a terminal operation such as collect() 3 .  References:   Comparator (Java SE 17 & JDK 17) ,  Comparable (Java SE 17 & JDK 17) ,  Stream (Java SE 17 & JDK 17)

The answer is D because the code fragment reads the content of the in.txt file and writes it to the out.txt file. The content of the in.txt file is “23456789”. The code fragment uses a char array buffer of size 8 to read the content of the in.txt file. The while loop reads the content of the in.txt file and writes it to the out.txt file until the end of the file is reached. Therefore, the content of the out.txt file will be “0123456789”.

The code creates two threads, t1 and t2, and starts them. The threads will print their names and the value of the Atomic Integer object, x, which is initially set to 1. The threads will then increment the value of x and print their names and the new value of x. Since the threads are started at the same time, the output will be in random order. However, the final output will always be t1 : 1 : t2: 1 : t1 : 2 : t2: 2:  References :  AtomicInteger (Java SE 17 & JDK 17) - Oracle

The code fragment will fail to compile because the play method in the Dog class is declared as private, which means that it cannot be accessed from outside the class. The main method is trying to call the play method on a Dog object, which is not allowed. Therefore, the code fragment will produce a compilation error.