A Review Of Verified 1z0-829 Preparation Exams

The code fragment is trying to obtain the java.io.Console object, which is a class that provides methods to access the character-based console device, if any, associated with the current Java virtual machine. The correct way to obtain the Console object is to call the static method Console console() in the java.lang.System class. This method returns the unique Console object associated with the current Java virtual machine, if any. Therefore, option A is correct, as it calls System.console() and assigns it to a Console variable. References:
✑ https://docs.oracle.com/javase/17/docs/api/java.base/java/io/Console.html
✑ https://docs.oracle.com/javase/17/docs/api/java.base/java/lang/System.html#cons ole()
✑ https://education.oracle.com/products/trackp_OCPJSE17
✑ https://mylearn.oracle.com/ou/learning-path/java-se-17-developer/99487

The answer is B and E because the module-info file should include a
provides directive and an exports directive to represent the service provider interface. The provides directive declares that the module provides an implementation of a service interface, which is com.transport.vehicle.cars.Car in this case. The with clause specifies the fully qualified name of the service provider class, which is com.transport.vehicle.cars.impl.CarImpl in this case. The exports directive declares that the module exports a package, which is com.transport.vehicle.cars in this case, to make it available to other modules. The package contains the service interface that other modules can use.
Option A is incorrect because requires is not the correct keyword to declare a service provider interface. Requires declares that the module depends on another module, which is not the case here.
Option C is incorrect because it has a typo in the module name. It should be com.transport.vehicle.cars, not cm.transport.vehicle.cars.
Option D is incorrect because it has a typo in the keyword provides. It should be provides, not Provides. It also has a typo in the service interface name. It should be com.transport.vehicle.cars.Car, not com.transport.vehicle.cars.Car impl. It also has an unnecessary to clause, which is used to limit the accessibility of an exported package to specific modules.
Option F is incorrect because it exports the wrong package. It should export com.transport.vehicle.cars, not com.transport.vehicle.cars.impl. The impl package contains the service provider class, which should not be exposed to other modules.
Option G is incorrect because it exports the wrong package. It should export com.transport.vehicle.cars, not com.transport.vehicle. The vehicle package does not contain the service interface or the service provider class. References:
✑ Oracle Certified Professional: Java SE 17 Developer
✑ Java SE 17 Developer
✑ OCP Oracle Certified Professional Java SE 17 Developer Study Guide
✑ Java Modules - Service Interface Module - GeeksforGeeks
✑ Java Service Provider Interface | Baeldung

The code fragment will execute the update statement and set the course fee of the course with ID 1021 to 5000. The executeUpdate method returns an int value that indicates the number of rows affected by the SQL statement. In this case, only one row will be updated, so the result variable will be 1. The if statement will check if the result is greater than 0, which is true, and print ??Updated successfully??. Therefore, the output of the code fragment is true. References: https://education.oracle.com/products/trackp_OCPJSE17, https://mylearn.oracle.com/ou/learning-path/java-se-17-developer/99487, https://docs.oracle.com/en/java/javase/17/docs/api/java.sql/java/sql/Statement.html#execut eUpdate(java.lang.String)

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 fragment will fail to compile because the parseInt method of the Integer class is a static method, which means that it can be invoked without creating an object of the class. However, the code is trying to invoke the parseInt method on an object of type Integer, which is not allowed. The correct way to invoke the parseInt method is by using the class name, such as Integer.parseInt (s). Therefore, the code fragment will produce a compilation error. References: Integer (Java SE 17 & JDK 17) - Oracle

The answer is B because a bottom-up migration is a strategy for modularizing an existing application by moving its dependencies to the module path one by one, starting from the lowest-level libraries and ending with the application itself. This way, each module can declare its dependencies on other modules using the module-info.java file, and benefit from the features of the Java Platform Module System (JPMS), such as reliable configuration, strong encapsulation, and service loading.
Option A is incorrect because a top-down migration is a strategy for modularizing an existing application by moving it to the module path first, along with its dependencies as automatic modules. Automatic modules are non-modular JAR files that are treated as modules with some limitations, such as not having a module descriptor or a fixed name. A top-down migration allows the application to use the module path without requiring all of its dependencies to be modularized first.
Option C is incorrect because a top-down migration does not require any specific order of migrating modules, as long as the application is moved first and its dependencies are moved as automatic modules. A bottom-up migration, on the other hand, requires the required modules to migrate before the modules that depend on them.
Option D is incorrect because unnamed modules are not automatic modules in any migration strategy. Unnamed modules are modules that do not have a name or a module descriptor, such as classes loaded from the class path or dynamically generated classes. Unnamed modules have unrestricted access to all other modules, but they cannot be accessed by named modules, except through reflection with reduced security checks. References:
✑ Oracle Certified Professional: Java SE 17 Developer
✑ Java SE 17 Developer
✑ OCP Oracle Certified Professional Java SE 17 Developer Study Guide
✑ Migrating to Modules (How and When) - JavaDeploy
✑ Java 9 Modularity: Patterns and Practices for Developing Maintainable
Applications

The code fragment is using the stream methods allMatch, anyMatch, noneMatch, and findFirst on a list of strings called specialDays. These methods are used to perform matching operations on the elements of a stream, such as checking if all, any, or none of the elements satisfy a given predicate, or finding the first element that matches a predicate1. The predicate in this case is that the string equals ??Labour?? or ??Halloween??. The output will be:
✑ False: because not all of the elements in specialDays are equal to ??Labour?? or ??Halloween??.
✑ true: because at least one of the elements in specialDays is equal to ??Labour?? or ??Halloween??.
✑ true: because none of the elements in specialDays are equal to both ??Labour?? and ??Halloween??.
✑ Optional[NewYear]: because the first element in specialDays that matches the predicate is ??NewYear??, and the findFirst method returns an Optional object that may or may not contain a non-null value2.
References: Stream (Java SE 17 & JDK 17), Optional (Java SE 17 & JDK 17)

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 order1. The compareTo() method is used to implement the Comparable interface, which defines the natural order of objects of a class2. 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 code snippet is an example of Java SE 17 code. The code is checking if the object is an instance of class C and if it is, it will print ??mC??. If it is not an instance of class C, it will print ??mA??. In this case, the object is not an instance of class C, so the output
will be ??mA??. References: Pattern Matching for instanceof - Oracle Help Center

The answer is D because the code fragment reads the file ??data.txt?? and collects all the lines in the file into a single string, separated by hyphens. Then, it prints the resulting string. Next, it attempts to read the fourth line in the file (index 3) and print it. However, since the file only has three lines, an IndexOutOfBoundsException is thrown. References:
✑ Oracle Certified Professional: Java SE 17 Developer
✑ Java SE 17 Developer
✑ OCP Oracle Certified Professional Java SE 17 Developer Study Guide
✑ Read contents of a file using Files class in Java

The answer is B because the code fragment contains a syntax error that prevents it from compiling. The code fragment tries to catch a StockException in line 10, but the catch block does not have a parameter of type StockException. The catch block should have a parameter of type StockException, such as:
catch (StockException e) { // handle the exception }
This is required by the Java syntax for the catch clause, which must have a parameter that is a subclass of Throwable. Without a parameter, the catch block is invalid and causes a compilation error.
Option A is incorrect because the program does not throw a StockException, as it does not compile.
Option C is incorrect because the program does not throw an OutofStockException, as it does not compile.
Option D is incorrect because the program does not throw a ClassCastException, as it does not compile. References:
✑ Oracle Certified Professional: Java SE 17 Developer
✑ Java SE 17 Developer
✑ OCP Oracle Certified Professional Java SE 17 Developer Study Guide
✑ The try-with-resources Statement (The Java™ Tutorials > Essential Classes > Exceptions)
✑ The catch Blocks (The Java™ Tutorials > Essential Classes > Exceptions)

The answer is C because the code demonstrates the concept of method overloading and type conversion in Java. Method overloading allows different methods to have the same name but different parameters. Type conversion allows values of one data type to be assigned to another data type, either automatically or explicitly. In the code, the class Test has four methods named sum, each with different parameter types: int, float, and double. The main method creates an instance of Test and calls the sum method with different arguments. The compiler will choose the most specific method that matches the arguments, based on the following rules:
✑ If there is an exact match between the argument types and the parameter types, that method is chosen.
✑ If there is no exact match, but there is a method with compatible parameter types, that method is chosen. Compatible types are those that can be converted from one to another automatically, such as int to long or float to double.
✑ If there is more than one method with compatible parameter types, the most specific method is chosen. The most specific method is the one whose parameter types are closest to the argument types in terms of size or precision.
In the code, the following method calls are made:
✑ test.sum(10, 10.5) -> This matches the sum(int a, float b) method exactly, so it is chosen. The result is 20.5, which is converted to int and printed as 20 (B).
✑ test.sum(10) -> This does not match any method exactly, but it matches the sum(double a) method with compatible types, as int can be converted to double automatically. The result is 10.0, which is printed as 10 (A).
✑ test.sum(10.5, 10) -> This does not match any method exactly, but it matches two methods with compatible types: sum(float a, float b) and sum(double a, double b). The latter is more specific, as double is closer to the argument types than float. The result is 20.5, which is printed as 20 (D).
Therefore, the output is B A D. References:
✑ Oracle Certified Professional: Java SE 17 Developer
✑ Java SE 17 Developer
✑ OCP Oracle Certified Professional Java SE 17 Developer Study Guide
✑ Method Overloading in Java
✑ Type conversion in Java with Examples
✑ Java Method Overloading with automatic type conversions

The answer is C because the code fragment given is an abstract sealed interface SInt that permits Story and Art. The correct answer is option C, which is a sealed interface Story that extends SInt and a non-sealed class Art that implements SInt. This is because a sealed interface can only be extended by the classes or interfaces that it permits, and a non-sealed class can implement a sealed interface.
Option A is incorrect because interface is misspelled as interace, and Story and Art should be capitalized as they are the names of the permitted classes or interfaces.
Option B is incorrect because public is misspelled as public, and sInd should be SInt as it is the name of the sealed interface.
Option D is incorrect because a non-sealed interface cannot extend a sealed interface, as it would violate the restriction of permitted subtypes.
Option E is incorrect because both Story and Art cannot be non-sealed interfaces, as they
would also violate the restriction of permitted subtypes.
References:
✑ Oracle Certified Professional: Java SE 17 Developer
✑ Java SE 17 Developer
✑ OCP Oracle Certified Professional Java SE 17 Developer Study Guide
✑ Sealed Classes and Interfaces in Java 15 | Baeldung
✑ Sealed Class in Java - Javatpoint

The code is defining an enum class called Forecast with three values: SUNNY, CLOUDY, and RAINY. The toString() method is overridden to always return ??SNOWY??. In the main method, the ordinal value of SUNNY is printed, which is 0, followed by the value of CLOUDY converted to uppercase, which is ??CLOUDY??. However, since the
toString() method of Forecast returns ??SNOWY?? regardless of the actual value, the output
will be ??0 SNOWY??. References: Enum (Java SE 17 & JDK 17), Enum.EnumDesc (Java SE 17 & JDK 17)

The code fragment is creating a string variable ??a?? with the value ??Hello! Java??. Then, it is printing the index of ??Java?? in ??a??. Next, it is replacing ??Hello!?? with ??Welcome!?? in ??a??. Then, it is printing the index of ??Java?? in ??a??. Finally, it is creating a new StringBuilder object ??b?? with the value of ??a?? and printing the index of ??Java?? in ??b??. The output will be 8109 because the index of ??Java?? in ??a?? is 8, the index of ??Java?? in ??a?? after replacing ??Hello!?? with ??Welcome!?? is 10, and the index of ??Java?? in ??b?? is 9. References: Oracle Java SE 17 Developer source and documents: [String (Java SE 17 & JDK 17)], [StringBuilder (Java SE 17 & JDK 17)]