What is the main disadvantage of the Bubble Sort algorithm in terms of performance?
- It has a time complexity of O(n^2) in the worst case, making it inefficient for large datasets.
- It is not a stable sorting algorithm, leading to unpredictable results when sorting objects with equal keys.
- It is not an in-place sorting algorithm, which means it requires additional memory for sorting.
- It requires additional memory space to perform sorting, increasing its space complexity.
The main disadvantage of Bubble Sort is its worst-case time complexity of O(n^2), which makes it inefficient for sorting large datasets. It is a comparison-based sorting algorithm, and its performance degrades significantly as the dataset size increases. Its stability and in-place sorting characteristics are not the primary factors affecting its performance.
To access or modify the private fields in a class, you should use ________ methods.
- accessor
- constructor
- mutator
- public
To access or modify private fields in a class, you should use "mutator" methods, also known as setter methods. These methods are designed to set or modify the private field values, maintaining control over access.
The method overriding is also known as ________ time polymorphism.
- compile-time
- dynamic
- runtime
- static
Method overriding is a form of polymorphism that occurs at runtime, making it dynamic polymorphism. It allows the actual method to be determined at runtime based on the object's type, which is why it's also known as runtime polymorphism.
In a class instance, synchronized blocks can be used to avoid locking the entire method and only lock ________.
- the class instance
- the instance itself
- the method
- the thread
In Java, synchronized blocks allow you to lock specific portions of a method rather than locking the entire method. By using synchronized blocks, you can choose what specific data or code you want to protect from concurrent access by specifying the object that should serve as the lock, commonly referred to as "the method's ________."
How can you access variables in the surrounding scope from a lambda expression?
- They are automatically accessible within the lambda.
- You can access them using the super keyword.
- You cannot access them.
- You need to pass them as parameters to the lambda expression.
To access variables from the surrounding scope within a lambda expression, you typically need to pass them as parameters to the lambda expression. This is known as "capturing" variables. Lambda expressions in Java can access effectively final local variables and instance variables. Attempting to access non-final variables can result in compilation errors.
The method ________ is used to execute SQL for DDL statements using JDBC.
- executeDDL()
- executeQuery()
- executeStatement()
- executeUpdate()
In JDBC, the method executeUpdate() is used to execute SQL statements that perform Data Definition Language (DDL) operations, such as creating, altering, or dropping database objects. It returns an integer representing the number of rows affected by the statement. executeQuery() is used for retrieving data, not DDL statements.
If a class has multiple constructors, it can be said to have constructor ________.
- chaining
- overloading
- overriding
- polymorphism
When a class has multiple constructors with different parameter lists, it is said to have constructor overloading. Constructor overloading allows you to create multiple constructors in the same class, each with a different set of parameters. This is a form of method overloading specific to constructors. Constructor overriding is not a valid term in Java.
The ________ method is used to move the thread into the Ready/Runnable state.
- join()
- sleep()
- start()
- wait()
The "start()" method is used to move a thread into the Ready/Runnable state in Java. When a thread is started using "start()", it becomes eligible for execution, and the JVM schedules it for execution at the appropriate time.
What is the role of the JavaFX Application Thread?
- To execute long-running tasks without affecting the application's responsiveness.
- To handle background tasks and data processing in a JavaFX application.
- To manage the user interface (UI) and handle user input events.
- To synchronize communication between the server and the client.
The JavaFX Application Thread, also known as the JavaFX UI thread, is responsible for managing the user interface (UI) and handling user input events in a JavaFX application. It ensures that UI updates and event handling are done in a thread-safe manner, preventing UI freezes and glitches. This thread is crucial for providing a responsive and smooth user experience in JavaFX applications.
What will be the output of the following code snippet: System.out.println(10 + 20 + "Hello" + 30 + 40);?
- 100200Hello3040
- 1020Hello3040
- 5070Hello
- Hello10203040
In Java, when you use the + operator with both numbers and strings, it performs left-to-right addition. So, the numbers are added first, and then the result is concatenated with the strings. The correct output is "1020Hello3040."