Free Oracle 1z0-829 Practice Exam with Questions & Answers

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 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 answer is C because the code fragment contains a syntax error in line 7, where the method display is declared without any parameter type. This causes a compilation error, as Java requires the parameter type to be specified for each method parameter. To fix this error, the parameter type should be added before the parameter name, such as string design. This will enable the code to compile and run without any errors. References:

• Oracle Certified Professional: Java SE 17 Developer
• Java SE 17 Developer
• OCP Oracle Certified Professional Java SE 17 Developer Study Guide
• Java Methods

The code fragment is trying to read an object from a file using the ObjectInputStream class. This class throws an IOException and a ClassNotFoundException. To handle these exceptions, the main method signature should declare that it throws these exceptions. Otherwise, the code will not compile. If the main method throws these exceptions, the code will print Wagon : 200, which is the result of calling the toString method of the LuxuryCar object that was written to the file. References: ObjectInputStream (Java SE 17 & JDK 17) - Oracle, ObjectOutputStream (Java SE 17 & JDK 17) - Oracle

The two code fragments that compile are B and E. These are the only ones that use the correct syntax for declaring and initializing a var variable. The var keyword is a reserved type name that allows the compiler to infer the type of the variable based on the initializer expression. However, the var variable must have an initializer, and the initializer must not be null or a lambda expression. Therefore, option A is invalid because it does not have an initializer, option C is invalid because it has a null initializer, and option D is invalid because it has a lambda expression as an initializer. Option B is valid because it has a String initializer, and option E is valid because it has an int initializer.

https://docs.oracle.com/en/java/javase/17/language/local-variable-type-inference.html

The 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 Center

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 fragment is using the switch statement with the new Java 17 syntax. The switch statement checks the value of the variable desig and executes the corresponding case statement. In this case, the value of desig is “CTO”, which does not match any of the case labels. Therefore, the default case statement is executed, which prints “Undefined”. The other case statements are not executed, because there is no fall through in the new syntax. Therefore, the output of the code fragment is:

Undefined

 An 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.

The code fragment is using the bitwise operators & (AND), | (OR), and ^ (XOR) to perform operations on the binary representations of the integer values. The & operator returns a 1 in each bit position where both operands have a 1, the | operator returns a 1 in each bit position where either operand has a 1, and the ^ operator returns a 1 in each bit position where only one operand has a 1. The binary representations of the integer values are as follows:

• 1000 = 1111101000
• 100 = 1100100
• 101 = 1100101

The code fragment performs the following operations:

• x = x ^ y; // x becomes 1111010101, which is 1001 in decimal
• y = x ^ y; // y becomes 1100100, which is 100 in decimal
• x = x ^ y; // x becomes 1100101, which is 101 in decimal

The code fragment then prints out the values of x, y, and z, which are 1001, 100, and 1000 respectively. Therefore, option D is correct.