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👨‍💻 Java Coding Challenge

A. Start of the week
B. Midweek
C. End of the week

⬇️ Guess the code output in the comments!

👨‍💻 Java Interview Question with answer

❓ Question:
What is the purpose of the finalize() method in Java, and is it still recommended for use?

🤔 Answer:
The finalize() method in Java was originally designed as a mechanism to perform cleanup operations before an object is garbage collected. It is a method defined in the Object class, which means every class in Java inherits it. The intention behind finalize() was to provide a way to clean up non-memory resources like file handles or database connections before an object is removed from memory.

How `finalize()` Works:
- Invocation by Garbage Collector: The finalize() method is called by the garbage collector on an object when it determines that there are no more references to the object. The method gives the object an opportunity to perform any necessary cleanup before the object is reclaimed.
- Unpredictable Execution: The execution of finalize() is not guaranteed to be prompt or predictable. The garbage collector is free to ignore finalization, and the method might never be called if the program terminates before garbage collection occurs.
- Resource Management Issues: Due to its unpredictable nature, relying on finalize() for resource management can lead to various issues, including memory leaks and inconsistent resource states.

Deprecation and Alternatives:
- Deprecation: As of Java 9, the finalize() method has been deprecated due to its many limitations and the availability of better alternatives.
- Alternatives: Modern Java applications should use other mechanisms for cleanup, such as:
- Try-with-resources: Introduced in Java 7, this construct ensures that resources are closed automatically at the end of a block. It is especially useful for managing resources like files and streams.

    try (BufferedReader br = new BufferedReader(new FileReader("file.txt"))) {
        // Use the resource
    } catch (IOException e) {
        e.printStackTrace();
    }
    

- Finally Block: The finally block in a try-catch statement guarantees that certain code (typically cleanup code) will always run, regardless of whether an exception is thrown or not.
- Explicit Cleanup Methods: Implementing explicit methods (like `close()`) that handle the cleanup of resources and ensuring they are called at the right time.

Due to its unpredictable behavior and the advent of more reliable and efficient cleanup mechanisms, the use of finalize() is no longer recommended. Developers should prefer modern constructs like try-with-resources and explicit resource management methods for handling cleanup.

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👨‍💻 Java Quiz

Which keyword is used to refer to the parent class in Java?

A. super
B. parent
C. this

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👨‍💻 Java Interview Coding Task

Implement a method that rotates an array to the right by a given number of steps:

int[] rotateArray(int[] numbers, int steps) {
    // TODO: implement
}

Example Solution:

int[] rotateArray(int[] numbers, int steps) {
    int length = numbers.length;
    steps = steps % length;
    reverse(numbers, 0, length - 1);
    reverse(numbers, 0, steps - 1);
    reverse(numbers, steps, length - 1);
    return numbers;
}

private void reverse(int[] array, int start, int end) {
    while (start < end) {
        int temp = array[start];
        array[start] = array[end];
        array[end] = temp;
        start++;
        end--;
    }
}

⬇️ Share your solution in the comments!

👨‍💻 SQL Quiz

Which SQL statement is used to remove a record from a table?

A. REMOVE
B. DELETE
C. ERASE

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👨‍💻 Java Coding Challenge

A. 9
B. 10
C. 9.78

⬇️ Guess the code output in the comments!

👨‍💻 Java Interview Question with answer

❓ Question:
What is the difference between method overloading and method overriding in Java?

🤔 Answer:
In Java, method overloading and method overriding are two ways to achieve polymorphism, but they are used in different contexts and serve different purposes.

Method Overloading:
- Definition: Method overloading occurs when two or more methods in the same class have the same name but different parameters (different type, number, or order of parameters).
- Compile-Time Polymorphism: It is a compile-time polymorphism, meaning the method to be called is determined at compile time.
- Use Case: Overloading is useful when methods perform similar but slightly different functions. It improves code readability by keeping related methods under a single name.

  class Example {
      void display(int a) {
          System.out.println("Arguments: " + a);
      }

      void display(int a, int b) {
          System.out.println("Arguments: " + a + " and " + b);
      }

      void display(double a) {
          System.out.println("Arguments: " + a);
      }
  }
  

Method Overriding:
- Definition: Method overriding occurs when a subclass provides a specific implementation for a method already defined in its superclass. The method in the subclass should have the same name, return type, and parameters as the method in the superclass.
- Runtime Polymorphism: It is a runtime polymorphism, meaning the method to be called is determined at runtime based on the object's type.
- Use Case: Overriding is used to provide a specific implementation of a method that is already defined in the superclass, allowing the subclass to offer a behavior that is specific to its type.

  class Parent {
      void display() {
          System.out.println("Display method in Parent class");
      }
  }

  class Child extends Parent {
      @Override
      void display() {
          System.out.println("Display method in Child class");
      }
  }

  public class Main {
      public static void main(String[] args) {
          Parent obj = new Child();
          obj.display();  // Output: Display method in Child class
      }
  }
  

Key Differences:
- Parameters: Overloading involves different parameter lists, while overriding involves the same parameter list.
- Scope: Overloading happens within a single class, while overriding happens in a subclass.
- Binding: Overloading is resolved at compile time (static binding), while overriding is resolved at runtime (dynamic binding).
- Annotation: Overriding methods in Java are typically annotated with @Override to indicate that they override a method in the superclass.

Understanding these differences helps in designing flexible and maintainable code, utilizing the power of polymorphism effectively.

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👨‍💻 Java Quiz

Which keyword is used to prevent a class from being inherited in Java?

A. final
B. static
C. private

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