B. collect(Collectors.toList()) Here's why: A. forEach(): This method is used for side effects on each element in the stream, not for collecting results into a List. It's not inherently thread-safe for modifying a collection concurrently. C. parallelStream(): This method simply creates a parallel stream from the original collection. It doesn't address thread safety during collection. D. stream(): This method creates a sequential stream. While it avoids the issue of parallel processing, it doesn't guarantee thread safety if the original collection is being modified concurrently. Collectors.toList(): When used with collect(), this collector provides thread-safe collection of elements from the stream into a new ArrayList instance. Java internally uses a thread-safe mechanism to handle concurrent additions to the list during parallel processing. Alternative for Thread Safety: CopyOnWriteArrayList: If you need to modify the original collection within the stream and maintain thread safety, consider using a CopyOnWriteArrayList instead of a regular List. This collection creates a copy of itself whenever a modification occurs, ensuring that the original list remains unmodified during the parallel processing. Example: Java import java.util.List; 39/97 import java.util.stream.Collectors; import java.util.stream.Stream; public class ThreadSafeCollection { public static void main(String[] args) { List numbers = List.of(1, 2, 3, 4, 5); // Option 1: Using collect(Collectors.toList()) List doubledNumbers = numbers.stream() .parallel() .map(number -> number * 2) .collect(Collectors.toList()); // Option 2: Using CopyOnWriteArrayList (if original list needs modification) List originalList = new CopyOnWriteArrayList<>(numbers); List tripledNumbers = originalList.stream() .parallel() .map(number -> number * 3) .collect(Collectors.toList()); System.out.println("Doubled numbers (thread-safe): " + doubledNumbers); System.out.println("Tripled numbers (thread-safe with CopyOnWriteArrayList): " + tripledNumbers); System.out.println("Original list remains unmodified: " + originalList); // If using CopyOnWriteArrayList } } In this example, both approaches ensure thread-safe collection: Option 1 uses collect(Collectors.toList()) for a new ArrayList creation within the parallel stream. Option 2 demonstrates using a CopyOnWriteArrayList as the original collection, ensuring thread safety even if the original list is being modified.

B. Modules require explicit declaration of dependencies on other modules. Here's why the other statements are incorrect: (a): Modules by default only have access to their own packages and public members of explicitly declared dependencies. Uncontrolled access would defeat the purpose of modularity and encapsulation. (c): Reflection can be used to access private members within the same module, but it generally cannot bypass module boundaries for private members of other modules. This helps enforce encapsulation and prevents unintended access. (d): Services and providers are a concept related to the Java module system. They allow modules to discover and interact with implementations of specific functionalities without directly depending on the implementation details.

C. java List numbers = Arrays.asList(10, 5, 20, 1); int max = numbers.stream().reduce(Integer::max).get(); Here's why the other options are incorrect: (a): filter and findFirst are for filtering and finding the first element that meets a condition. They don't perform reduction to get the maximum value. (b): max with Integer::compareTo uses a comparator to find the maximum element based on comparison. However, it doesn't perform a reduction operation. It returns an Optional containing the maximum value. (d): This code snippet uses max but retrieves the result as an Optional. For reduction operations, you typically call get on the Optional to extract the actual value. Explanation of the correct option (c): List numbers = Arrays.asList(10, 5, 20, 1);: This line assumes you have a list of integers. numbers.stream(): This converts the List to a Stream. .reduce(Integer::max): This part uses the reduce method with Integer::max as the binary operator. reduce performs a reduction operation by applying the binary operator (Integer::max in this case) to each element of the stream and an initial value (which is optional here). Integer::max is a method reference 63/97 that compares two integers and returns the larger one. Since no initial value is provided, the first element of the stream becomes the initial value for comparison. The result of reduce is the maximum value found after comparing all elements. .get(): This calls the get method on the result (which is an Optional in this case) to extract the actual maximum value.

D. Stream#forEachParallel() Here's why the other options are not ideal for concurrent iteration: A. for loop and b) while loop: These traditional loop constructs are not inherently thread-safe. If multiple threads try to modify the collection concurrently while iterating using these loops, you might encounter race conditions and data corruption. C. Iterator#next() : While Iterator provides a way to iterate over a collection, it doesn't guarantee thread safety. It's essential to use the collection's appropriate methods or concurrent collection implementations for safe concurrent iteration. Stream#forEachParallel(): This method belongs to the Java Streams API and is specifically designed for parallel processing of elements in a collection. It leverages multiple threads to process elements concurrently, potentially improving performance for large collections. It's important to note that forEachParallel() is used for side effects on each element (like printing) and not for collecting results into a new collection. If you need thread-safe collection, consider using collect() with appropriate collectors. Thread Safety Considerations: While forEachParallel() enables concurrent iteration, it doesn't guarantee the order in which elements are processed. The order might be non-deterministic. 47/97 If your operations within the loop require maintaining order or involve modifications to the original collection, you might need additional synchronization mechanisms or use concurrent collection implementations like CopyOnWriteArrayList.

C. PrintStream Here's a breakdown of the other options and why they are not used for console output: A. System.out.println() is a method, not a class. It's a convenient way to write formatted output to the standard output stream, which is typically the console. However, System.out itself is a PrintStream object. B. FileOutputStream is used for writing data to a file, not the console. D. BufferedReader is used for reading text data from a character stream, not writing to the console. 28/97 PrintStream Class: The PrintStream class provides methods for writing formatted and unformatted data to an output stream. The System.out object in Java is an instance of PrintStream that is pre-configured to write to the standard output stream (usually the console). Here's an example of using System.out.println() for console output: Java System.out.println("Hello, world!"); This code snippet utilizes the println() method of the System.out object (which is a PrintStream) to write the string "Hello, world!" followed by a newline character to the console.

B. To provide a mechanism for querying specific information from temporal objects. Here's a breakdown of why this is the answer and the other options are not as relevant: Querying Information: The TemporalQueries interface defines a strategy for extracting specific pieces of information from temporal objects (objects representing dates, times, or time zones). You can use this interface to query for various fields like year, month, day of month, or specific offsets within a time zone. Not for Manipulation: While temporal objects can be manipulated using methods like plusDays() or withHour(), the TemporalQueries interface is specifically for querying information without directly modifying the temporal object itself. Calendar Systems: The TemporalQueries interface doesn't directly deal with representing different calendar systems. Java provides separate classes like ChronoLocalDate for handling non-ISO calendar systems. Formatting: Formatting temporal objects for display is handled by the DateTimeFormatter class. TemporalQueries focuses on extracting information for calculations or other logic. Example: Java LocalDate today = LocalDate.now(); int year = today.query(TemporalQueries.year()); boolean isLeapYear = today.isLeapYear(); // Alternative way to check leap year System.out.println("Year: " + year); In this example, we use the query() method with TemporalQueries.year() to extract the year from the today object. This demonstrates how the TemporalQueries interface allows you to retrieve specific information from temporal objects.

A. java List names = Arrays.asList("Alice", "Bob", "Charlie"); String allNames = names.stream().collect(Collectors.joining(",")); Here's why this option is correct: .collect(Collectors.joining(",")): This part uses the collect operation with the Collectors.joining collector. The joining collector is specifically designed for joining elements of a stream into a single String. You can specify a delimiter (", " in this case) to separate the elements in the joined String. The other options have limitations: B. StringBuilder sb = new StringBuilder(); ... sb.toString().substring(0, sb.length() - 1);: This approach uses a StringBuilder to manually append each element with a comma. While it works, it's less concise and efficient than using the Collectors.joining collector. The substring at the end is necessary to remove the trailing comma added after the last element C. String allNames = ""; names.stream().forEach(n -> allNames += n + ",");: This option also performs manual concatenation within a forEach loop. String concatenation within loops is generally less efficient than using a dedicated collector like Collectors.joining. Additionally, modifying a String object repeatedly within the loop can be less performant. Important Note: D. List names = Arrays.asList("Alice", null, "Charlie"); ...: The provided code snippet (regardless of the chosen option) would fail if the names list contains a null value. Streams cannot handle null values by default. You'll need to handle null values explicitly before using collect or any other stream operations. You can filter out null values or use a custom joining function that handles nulls appropriately

C. fruits.addLast("Apple"); Here's why: LinkedList: This data structure represents a linear list where elements are linked together using pointers. addLast(String element): This method is specifically designed for adding a new element to the end of a LinkedList. It takes the element to be added as an argument. The other options have issues: A. fruits.addFirst("Apple");: This method adds the element "Apple" to the beginning of the LinkedList, not the end. B. fruits.set(fruits.size(), "Apple");: This approach attempts to set the element at the index equal to the current size of the list. However, fruits.size() refers to the number of elements, and trying to set an element at that index would result in an IndexOutOfBoundsException because the list doesn't have an element at that position yet. D. fruits.append("Apple");: There's no built-in append method for LinkedList in Java. You should use the standard addLast method for adding elements to the end. Example: Java LinkedList fruits = new LinkedList<>(); fruits.add("Banana"); fruits.add("Orange"); fruits.addLast("Apple"); // Add "Apple" to the end System.out.println(fruits); // Output: [Banana, Orange, Apple]

B. Analyzes dependencies between modules and classes. Here's why the other options are incorrect: (a): Jdeps is not for creating runtime images. Tools like jlink are used for that purpose. (c): Jdeps is not for documentation generation. Tools like Javadoc are used for that. (d): Jdeps is not a compiler. Javac is the tool used for compiling Java source code. Explanation: Jdeps is a command-line tool included in the Java Development Kit (JDK) starting from version 8. It's a static analysis tool that helps developers understand the dependencies between modules and classes in a Java application. Jdeps can analyze: Class file dependencies: It identifies which classes depend on other classes. JAR file dependencies: It shows which JAR files an application or library depends on. Module dependencies (Java 9 and above): It analyzes dependencies between modules in a modular project. By using jdeps, developers can: Identify unused dependencies. Refactor code to reduce dependencies and improve modularity. Prepare for migration to a modular project structure (Java 9 and above).

B. To provide a callback mechanism for lambda expressions. Explanation: Functional interfaces, introduced in Java 8, play a crucial role in enabling functional programming paradigms within the object-oriented framework of Java. They achieve this by: Single Abstract Method (SAM): Functional interfaces can have only one abstract method. This single method signature acts as a blueprint for anonymous functions or lambda expressions. Lambda expressions can be used as arguments to methods or passed to higher-order functions, providing concise and flexible ways to define behavior. For example: Java @FunctionalInterface // Optional annotation for clarity public interface StringProcessor { String process(String str); } String result = processString("Hello", str -> str.toUpperCase()); // Lambda expression used as argument private String processString(String str, StringProcessor processor) { return processor.process(str); // Functional interface used for callback } Incorrect statements and explanations: A. Functional interfaces are not specifically designed to define static helper methods. While they can potentially hold static methods, their main focus is defining a single abstract method for lambda expressions C. Functional interfaces don't enforce specific naming conventions for methods. The method name and signature define the behavior expected from the implementing class or lambda expression. D. Functional interfaces primarily deal with method functionality, not access restriction. The visibility of methods within an interface is usually public or protected, depending on the design.