Which of the following is true regarding the flow of control in a try-catch-finally statement?
- The catch block is executed before finally.
- The catch block is optional.
- The code inside try is optional.
- The finally block is executed before try.
In a try-catch-finally statement in Java, the flow of control is such that the try block is executed first. If an exception occurs within the try block, control is transferred to the appropriate catch block (if matching). Finally block is executed after try (whether an exception occurred or not), making it suitable for cleanup code.
In a switch case, the ________ keyword is used to specify the code that should be executed if no case matches.
- default
- defaultcase
- else
- fallback
In a switch case in Java, the default keyword is used to specify the code that should be executed if none of the case labels match the switch expression. It acts as a fallback or default option when no other case matches the switch expression.
What is the primary purpose of using synchronized methods in Java?
- To ensure that a method is only accessible within the same package.
- To make a method private and inaccessible.
- To optimize the execution speed of a method.
- To prevent multiple threads from accessing and modifying shared resources simultaneously.
Synchronized methods in Java are used primarily to prevent multiple threads from accessing and modifying shared resources simultaneously, ensuring thread safety. This is crucial in multithreading scenarios where multiple threads may otherwise interfere with each other when accessing shared data.
Which Java method is used to establish a connection to a specified URL?
- URLConnect()
- connectToURL()
- establishConnection()
- openConnection()
To establish a connection to a specified URL in Java, you use the openConnection() method provided by the URL class. This method returns a URLConnection object, which can be used to interact with the resource located at the URL.
What is the worst-case time complexity of the Quick Sort algorithm?
- O(log n)
- O(n log n)
- O(n)
- O(n^2)
The worst-case time complexity of the Quick Sort algorithm is O(n^2). However, on average, it has a time complexity of O(n log n), making it a very efficient sorting algorithm for large datasets. The worst-case scenario occurs when the pivot chosen is always the smallest or largest element, resulting in unbalanced partitions.
What will be the output of the following code snippet: System.out.println("Java".concat("Programming"))?
- Compilation Error
- Java Programming
- JavaProgramming
- ProgrammingJava
The concat() method in Java combines two strings, and in this case, it appends "Programming" to "Java," resulting in "JavaProgramming." Therefore, the correct output is "JavaProgramming."
Which method is used to obtain the result from a Future object?
- fetchResult()
- get()
- getResult()
- obtainResult()
The get() method is used to obtain the result from a Future object in Java. This method is called on a Future instance, and it blocks until the result is available if it's not already computed. It returns the result of the computation or throws an exception if the computation encountered an error.
Imagine you are developing a multi-module application where some modules will be developed by third-party vendors. How would you ensure that the third-party modules adhere to a certain API but do not inherit default method implementations?
- Provide a detailed API documentation to third-party vendors, leaving it to them to ensure API adherence without enforcing a specific coding approach.
- Use a combination of interfaces and abstract classes, allowing third-party vendors to choose between them based on their needs.
- Use abstract classes for the API, providing method stubs without default implementations, and have third-party vendors extend these classes to implement the API.
- Use interfaces with default methods for the API, allowing third-party vendors to implement the interface while overriding the default methods as needed.
In this scenario, using abstract classes for the API is the preferred choice. Abstract classes provide method stubs without default implementations, ensuring that third-party vendors must implement the required methods while giving them flexibility in their approach. Interfaces with default methods could lead to unwanted method inheritance.
Can we overload Java main method?
- No, main method overloading is not allowed in Java.
- Yes, by changing the access modifiers.
- Yes, by changing the number or type of parameters.
- Yes, by changing the return type.
In Java, you can overload the main method by changing the number or type of parameters. However, only the standard public static void main(String[] args) method is recognized as the entry point of a Java program. Overloading main with different parameter types won't be recognized as the program's entry point. The JVM expects the standard main method signature.
The FXMLLoader class is utilized to load ________ files.
- FXML
- JavaFX
- UI
- XML
The FXMLLoader class in JavaFX is used to load FXML (FXML Markup Language) files. FXML files are typically used for defining the user interface of JavaFX applications in a declarative manner. The other options, JavaFX, UI, and XML, are not the files loaded by the FXMLLoader.