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Which method is used to retrieve the protocol type of a URL in Java?

  • fetchProtocol()
  • getProtocol()
  • getURLProtocol()
  • retrieveProtocol()
In Java, to retrieve the protocol type of a URL, you should use the getProtocol() method of the URL class. It returns a String containing the protocol, such as "http," "https," "ftp," etc. The other options do not exist as valid methods for this purpose.
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Can we overload the "+" operator to concatenate two strings and add two integers in a custom class?

  • No, Java does not support operator overloading.
  • Yes, by defining a method named + in the custom class.
  • Yes, by defining methods named add and concatenate for the custom class.
  • Yes, by using the + operator with different parameter types in the method definition.
No, Java does not support operator overloading. In Java, the + operator is not overloaded for user-defined classes. The + operator is only used for addition when applied to numeric data types and for string concatenation when used with strings. Therefore, you cannot define custom behavior for the + operator in user-defined classes.
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Does Java support operator overloading?

  • No, not at all.
  • Only for arithmetic ops.
  • Yes, for all operators.
  • Yes, for selected ops.
Java does not support operator overloading for custom classes. While some languages do allow operator overloading, Java enforces a fixed set of operators for built-in types, and you cannot create custom operator overloads. This limitation helps maintain code readability and prevents ambiguity.
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How can we handle SQL exceptions that may occur during the execution of a JDBC program?

  • Ignore them and let the program continue
  • Use assert statements to handle exceptions
  • Use if-else statements to handle exceptions
  • Use try-catch blocks to catch and handle exceptions
SQL exceptions in a JDBC program should be handled using try-catch blocks. Ignoring them can lead to unexpected program behavior, and try-catch allows you to gracefully handle errors, log them, or take corrective actions. The other options are not recommended approaches for handling exceptions in JDBC.
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To write primitive data types like int or double to a file in a machine-independent way, you might use ________.

  • DataOutputStream
  • FileInputStream
  • ObjectInputStream
  • ObjectOutputStream
To write primitive data types to a file in a machine-independent way, you can use DataOutputStream. It provides methods for writing different data types to a file while ensuring that the data can be read back correctly.
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A ________ block will always execute, whether an exception is thrown or not.

  • catch
  • finally
  • throw
  • try
The finally block is used to define a block of code that always executes, regardless of whether an exception is thrown or not. It's commonly used for cleanup operations such as closing files or releasing resources.
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Consider a scenario where you are designing a graphics system that includes different types of shapes (e.g., Circle, Rectangle). How would you decide between using an abstract class and an interface for defining common methods?

  • Use a concrete class and use inheritance to define common methods, as concrete classes can directly provide method implementations.
  • Use an abstract class with a base shape class and common methods, as abstract classes can provide both method implementations and fields.
  • Use an interface to define common methods, as interfaces allow for multiple inheritance and can be implemented by different shape classes.
  • Use both an abstract class and an interface, combining the advantages of both.
In this scenario, using an abstract class is appropriate because you can define common methods with default implementations in the base shape class. This provides code reusability and allows shape classes to inherit these methods. Interfaces can also be used, but they don't provide method implementations, making abstract classes a more suitable choice for this use case.
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Which searching algorithm requires the data to be sorted to work effectively?

  • Binary Search
  • Linear Search
  • Merge Sort
  • Quick Sort
Binary Search is an algorithm that requires the data to be sorted in ascending or descending order for effective searching. It uses the divide and conquer method and is not suitable for unsorted data.
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To update UI components from a non-JavaFX thread, use ________.

  • Platform.exit()
  • Platform.repaint()
  • Platform.runLater()
  • Platform.update()
To update UI components from a non-JavaFX thread in JavaFX, you should use the Platform.runLater() method. This method allows you to enqueue a Runnable object to be executed on the JavaFX Application Thread, ensuring that UI updates are performed on the correct thread to avoid concurrency issues.
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In which scenarios is it recommended to use synchronized blocks instead of synchronized methods?

  • When you don't want to use synchronization at all.
  • When you want to apply synchronization to a specific section of code within a method, providing more fine-grained control.
  • When you want to synchronize an entire method for simplicity.
  • When you want to synchronize multiple methods simultaneously.
Synchronized blocks are recommended when you want to apply synchronization to a specific section of code within a method, allowing more fine-grained control over synchronization. This can help reduce contention and improve performance in scenarios where synchronization is necessary. Synchronized methods are used when you want to synchronize the entire method for simplicity.
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