Java Programming - MCQ Practice Questions

What will be the output of the following code? FileOutputStream fos = new FileOutputStream("test.txt", true); What does the 'true' parameter indicate?

Which of the following best describes the relationship between InputStream and Reader classes?

In a scenario where you need to write formatted output (like printf), which class should be used?

What is the difference between read() and read(byte[] b) methods in InputStream?

Which exception is thrown when you try to serialize an object that contains non-serializable fields?

What is the purpose of the serialVersionUID field in a serializable class?

You need to read a file line by line efficiently. Which approach is best?

What happens if you try to read from a closed stream?

Which class wraps a byte stream to handle character encoding/decoding?

In the try-with-resources statement, what happens to resources automatically?

What is the main advantage of using RandomAccessFile over sequential streams?

When deserializing an object, which methods are called in order?

Consider a scenario where you need to read a large binary file efficiently without loading it entirely into memory. Which approach combines best practices?

What is the primary advantage of PushbackInputStream?

Which of the following classes is used to read primitive data types from an input stream in Java?

In a file I/O operation, you need to write objects to a file and later retrieve them. Which approach is most appropriate?

What will happen if you attempt to serialize a class that contains a non-serializable instance variable without declaring it as transient?

Consider a scenario where you're processing a 5GB log file and need to count specific error messages. Which I/O strategy would be most memory-efficient?

Which interface must a class implement to be eligible for serialization in Java, and what is the significance of implementing it with no abstract methods?

In a multi-threaded application, multiple threads are writing to the same file simultaneously using FileOutputStream. What is the primary issue and best solution?