This page was exported from Actual Test Materials [ http://blog.actualtests4sure.com ] Export date:Fri Nov 15 18:39:01 2024 / +0000 GMT ___________________________________________________ Title: 2024 Realistic Verified Free Oracle 1z1-829 Exam Questions [Q18-Q39] --------------------------------------------------- 2024 Realistic Verified Free Oracle 1z1-829 Exam Questions 1z1-829 Real Exam Questions and Answers FREE Oracle 1Z0-829 certification exam covers a wide range of topics related to Java SE 17, including advanced concepts such as functional programming, modules, and concurrency. Candidates are expected to have a thorough understanding of the Java programming language, as well as experience in developing and deploying Java applications in production environments.   QUESTION 18Given:Which statement is true?  The program throws StockException.  The program fails to compile.  The program throws outofStockException.  The program throws ClassCastException 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. Reference:Oracle Certified Professional: Java SE 17 DeveloperJava SE 17 DeveloperOCP Oracle Certified Professional Java SE 17 Developer Study GuideThe try-with-resources Statement (The Java™ Tutorials > Essential Classes > Exceptions) The catch Blocks (The Java™ Tutorials > Essential Classes > Exceptions)QUESTION 19Given:What is the result?  flipsflips  Compilation fails  flipsruns  runsflips  runsruns 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.QUESTION 20Given:What is the result?  flipsflips  Compilation fails  flipsruns  runsflips  runsruns ExplanationThe 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.QUESTION 21Given:Which statement is true?  The program throws StockException.  The program fails to compile.  The program throws outofStockException.  The program throws ClassCastException ExplanationThe 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 DeveloperJava SE 17 DeveloperOCP Oracle Certified Professional Java SE 17 Developer Study GuideThe try-with-resources Statement (The Java™ Tutorials > Essential Classes > Exceptions) The catch Blocks (The Java™ Tutorials > Essential Classes > Exceptions)QUESTION 22Given:Which two should the module-info file include for it to represent the service provider interface?  Requires cm.transport.vehicle,cars:  Provides.com.transport.vehicle.cars.Car with com.transport.vehicle.cars. impt, CatImpI;  Requires cm.transport.vehicle,cars:  Provides.com.transport.vehicle.cars.Car impl,CarImp1 to com.transport.vehicle.cars. Cars  exports com.transport.vehicle.cars.Car;  Exports com.transport.vehicle.cars;  Exports com.transport.vehicle; ExplanationThe 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 DeveloperJava SE 17 DeveloperOCP Oracle Certified Professional Java SE 17 Developer Study GuideJava Modules – Service Interface Module – GeeksforGeeksJava Service Provider Interface | BaeldungQUESTION 23Given:  Hello  Compilation fails  A NumberFormatException is thrown  there ExplanationThe 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) – OracleQUESTION 24Given:What is the result?  Software Game Chess 0  Software Game Software Game Chese 2  Software game write error  Software Game Software Game chess 0  Software Game Chess 2  Software Game read error ExplanationThe answer is B because the code uses the writeObject and readObject methods of the ObjectOutputStream and ObjectInputStream classes to serialize and deserialize the Game object. These methods use the default serialization mechanism, which writes and reads the state of the object’s fields, including the inherited ones. Therefore, the title field of the Software class is also serialized and deserialized along with the players field of the Game class. The toString method of the Game class calls the toString method of the Software class using super.toString(), which returns the value of the title field.Hence, when the deserialized object is printed, it shows “Software Game Software Game Chess 2”.References:Oracle Certified Professional: Java SE 17 DeveloperJava SE 17 DeveloperOCP Oracle Certified Professional Java SE 17 Developer Study GuideSerialization and Deserialization in Java with ExampleQUESTION 25Given the code fragment:What is the result?  Range 1Range 2Range 3  Range1Note a valid rank.  Range 1Range 2Range 3Range 1Not a valida rank  Range 1 ExplanationThe code fragment is using the switch statement with the new Java 17 syntax. The switch statement checks the value of the variable rank and executes the corresponding case statement. In this case, the value of rank is 4, so the first case statement is executed, printing “Range1”. The second and third case statements are also executed, printing “Range2” and “Range3”. The default case statement is also executed, printing “Not a valid rank”. References: Java Language Changes – Oracle Help CenterQUESTION 26Given the code fragment:Which code fragment invokes all callable objects in the workers set?         ExplanationThe code fragment in Option C invokes all callable objects in the workers set by using the ExecutorService’s invokeAll() method. This method takes a collection of Callable objects and returns a list of Future objects representing the results of the tasks. The other options are incorrect because they either use the wrong method (invokeAny() or submit()) or have syntax errors (missing parentheses or semicolons). References: AbstractExecutorService (Java SE 17 & JDK 17) – OracleQUESTION 27Given the code fragment:What is the result?  0  2  -2  220  111  12-4 ExplanationThe code fragment uses the Collections.binarySearch method to search for the string “e3” in the list. The first search returns the index of the element, which is 2. The second search returns the index of the element, which is 0. The third search returns the index of the element, which is -4. The final result is2. References: Collections (Java SE 17 & JDK 17) – OracleQUESTION 28Given:What is the result?  B A C  D A D  B A D  D D D 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. Reference:Oracle Certified Professional: Java SE 17 DeveloperJava SE 17 DeveloperOCP Oracle Certified Professional Java SE 17 Developer Study GuideMethod Overloading in JavaType conversion in Java with ExamplesJava Method Overloading with automatic type conversionsQUESTION 29Given the code fragment:Which code line n1, obtains the java.io.Console object?           ExplanationThe 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.htmlhttps://docs.oracle.com/javase/17/docs/api/java.base/java/lang/System.html#console()https://education.oracle.com/products/trackp_OCPJSE17https://mylearn.oracle.com/ou/learning-path/java-se-17-developer/99487QUESTION 30Given:What is the result?  4  2  6  Nothing is printed because of an indefinite loop.  Compilation fails.  5  A runtime exception is thrown.  3 ExplanationThe code will not compile because the variable ‘x’ is declared as final and then it is being modified in the switch statement. This is not allowed in Java. A final variable is a variable whose value cannot be changed once it is initialized1. The switch statement tries to assign different values to ‘x’ depending on the value of ‘y’, which violates the final modifier. The compiler will report an error: The final local variable x cannot be assigned. It must be blank and not using a compound assignment. References: The final Keyword (The Java™ Tutorials > Learning the Java Language > Classes and Objects)QUESTION 31Which statement is true about modules?  Automatic and unnamed modules are on the module path.  Only unnamed modules are on the module path.  Automatic and named modules are on the module path.  Only named modules are on the module path.  Only automatic modules are on the module path. A module path is a sequence of directories that contain modules or JAR files. A named module is a module that has a name and a module descriptor (module-info.class) that declares its dependencies and exports. An automatic module is a module that does not have a module descriptor, but is derived from the name and contents of a JAR file. Both named and automatic modules can be placed on the module path, and they can be resolved by the Java runtime. An unnamed module is a special module that contains all the classes that are not in any other module, such as those on the class path. An unnamed module is not on the module path, but it can read all other modules.QUESTION 32Given:Which statement is true while the program prints GC?  Only the object referenced by t2 is eligible for garbage collection.  Both the objects previously referenced by t1 are eligible for garbage collection.  None of the objects are eligible for garbage collection.  Only one of the objects previously referenced by t1 is eligible for garbage collection. QUESTION 33Assuming that the data, txt file exists and has the following content:Text1Text2Text3Given the code fragment:What is the result?  text1-text2-text3-text3  text1-text2-text3text1text2text3  text1-text2-text3A java.lang.indexoutofBoundsException is thrown.  text1-text2-text3text3 ExplanationThe 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 DeveloperJava SE 17 DeveloperOCP Oracle Certified Professional Java SE 17 Developer Study GuideRead contents of a file using Files class in JavaQUESTION 34Given the content of the in. tart file:23456789and the code fragment:What is the content of the out .txt file?  01234567801234  012345678  0123456789234567  0123456789  012345678901234  01234567 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”.QUESTION 35Given the code fragment:Which code fragment returns different values?  int sum = listOfNumbers. parallelStream () reduce (5, Integer:: sum) ;  int sum = listOfNumbers. Stream () reduce (5, (a, b) -> a + b) ;  int sum = listOfNumbers. Stream () reduce ( Integer:: sum) ; +5;  int sum = listOfNumbers. parallelStream () reduce ({m, n) -> m +n) orElse (5) +5;  int sum = listOfNumbers. Stream () reduce (0, Integer:: sum) + 5 ExplanationThe answer is C because the code fragment uses a different syntax and logic for the reduce operation than the other options. The reduce method in option C takes a single parameter, which is a BinaryOperator that combines two elements of the stream into one. The method returns an Optional, which may or may not contain a value depending on whether the stream is empty or not. The code fragment then adds 5 to the result of the reduce method, regardless of whether it is present or not. This may cause an exception if the Optional is empty, or produce a different value than the other options if the Optional is not empty.The other options use a different syntax and logic for the reduce operation. They all take two parameters, which are an identity value and a BinaryOperator that combines an element of the stream with an accumulator.The method returns the final accumulator value, which is equal to the identity value if the stream is empty, or the result of applying the BinaryOperator to all elements of the stream otherwise. The code fragments then add5 to the result of the reduce method, which will always produce a valid value.For example, suppose listOfNumbers contains [1, 2, 3]. Then, option A will perform the following steps:Initialize accumulator to identity value 5Apply BinaryOperator Integer::sum to accumulator and first element: 5 + 1 = 6 Update accumulator to 6 Apply BinaryOperator Integer::sum to accumulator and second element: 6 + 2 = 8 Update accumulator to 8 Apply BinaryOperator Integer::sum to accumulator and third element: 8 + 3 = 11 Update accumulator to 11 Return final accumulator value 11 Add 5 to final accumulator value: 11 + 5 = 16 Option B will perform the same steps as option A, except using a lambda expression instead of a method reference for the BinaryOperator. Option D will perform the same steps as option A, except using parallelStream instead of stream, which may change the order of applying the BinaryOperator but not the final result. Option E will perform the same steps as option A, except using identity value 0 instead of 5.Option C, however, will perform the following steps:Apply BinaryOperator Integer::sum to first and second element: 1 + 2 = 3 Apply BinaryOperator Integer::sum to previous result and third element: 3 + 3 = 6 Return Optional containing final result value 6 Add 5 to Optional value: Optional.of(6) + 5 = Optional.of(11) As you can see, option C produces a different value than the other options, and also uses a different syntax and logic for the reduce operation. References Oracle Certified Professional: Java SE 17 Developer Java SE 17 Developer OCP Oracle Certified Professional Java SE 17 Developer Study Guide Guide to Stream.reduce()QUESTION 36Given the code fragment:What is the result?  false 1false 2  true 1false 2  false 1ture 2  falase 0true 1 The code fragment is comparing the values of a, b, and c using the < and > operators. The first comparison, d, is checking if a is less than b and greater than c. Since a is equal to 2, b is equal to -2, and c is equal to -4, this comparison will evaluate to true. The second comparison, e, is checking if a is greater than b and a is greater than c. Since a is equal to 2, b is equal to -2, and c is equal to -4, this comparison will evaluate to false. Therefore, the result will be true 1 false 2. Reference: Operators (The Java™ Tutorials > Learning the Java Language – OracleQUESTION 37Assume you have an automatic module from the module path display-ascii-0.2. jar. Which name is given to the automatic module based on the given JAR file?  Display.ascii  Display-ascii-0.2  Display-ascii  Display-ascii-0 ExplanationAn automatic module name is derived from the name of the JAR file when it does not contain a module-info.class file. If the JAR file has an “Automatic-Module-Name” attribute in its main manifest, then its value is the module name. Otherwise, the module name is derived from the JAR file’s name by removing any version numbers and converting it to lower case. Therefore, for a JAR named display-ascii-0.2.jar, the automatic module name would be display-ascii, following these rules.QUESTION 38Given:What is the result?  Bicycle =7, car=7, motorcycle=7, truck=7)  (3:bicycle, 0:car, 0motercycle, 5:truck)  (Bicycle, car, motorcycle, truck)  Bicycle-1, car=3, motorcycle=1, truck=2)  Compilation fails. ExplanationThe answer is E because the code fragment contains several syntax errors that prevent it from compiling.Some of the errors are:The enum declaration is missing a semicolon after the list of constants.The enum constants are not capitalized, which violates the Java naming convention for enums.The switch expression is missing parentheses around the variable name.The case labels are missing colons after the enum constants.The default label is missing a break statement, which causes a fall-through to the next case.The println statement is missing a closing parenthesis and a semicolon.A possible corrected version of the code fragment is:enum Vehicle { BICYCLE, CAR, MOTORCYCLE, TRUCK; } public class Test { public static void main(String[] args) { Vehicle v = Vehicle.BICYCLE; switch (v) { case BICYCLE: System.out.print(“1”); break; case CAR: System.out.print(“3”); break; case MOTORCYCLE: System.out.print(“1”); break; case TRUCK: System.out.print(“2”); break; default: System.out.print(“0”); break; } System.out.println(); } } This would print 1 as the output. References:Oracle Certified Professional: Java SE 17 DeveloperJava SE 17 DeveloperOCP Oracle Certified Professional Java SE 17 Developer Study GuideEnum TypesThe switch StatementQUESTION 39Which statement is true?  The tryLock () method returns a boolean indicator immediately regardless if it has or has not managed to acquire the lock.  The tryLock () method returns a boolean indicator immediately if it has managed to acquire the lock, otherwise it waits for the lock acquisition.  The lock () method returns a boolean indicator immediately if it has managed to acquire the lock, otherwise it waits for the lock acquisition.  The Lock () method returns a boolean indicator immediately regardless if it has or has not managed to acquire the lock ExplanationThe tryLock () method of the Lock interface is a non-blocking attempt to acquire a lock. It returns true if the lock is available and acquired by the current thread, and false otherwise. It does not wait for the lock to be released by another thread. This is different from the lock () method, which blocks the current thread until the lock is acquired, and does not return any value. References:https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/concurrent/locks/Lock.html#tryLock(), 3, 4 Loading … Exam Dumps 1z1-829 Practice Free Latest Oracle Practice Tests: https://www.actualtests4sure.com/1z1-829-test-questions.html --------------------------------------------------- Images: https://blog.actualtests4sure.com/wp-content/plugins/watu/loading.gif https://blog.actualtests4sure.com/wp-content/plugins/watu/loading.gif --------------------------------------------------- --------------------------------------------------- Post date: 2024-06-29 10:47:29 Post date GMT: 2024-06-29 10:47:29 Post modified date: 2024-06-29 10:47:29 Post modified date GMT: 2024-06-29 10:47:29