Mastering Java: The Ultimate Quiz for 'Thinking in Java'

What does the StringBuilder class do in the BufferedInputFile example?

1. Reads data from the file

2. Converts bytes to characters

3. Accumulates the contents of the file

4. Buffers the file input

The correct answer is: Accumulates the contents of the file

The StringBuilder class in the BufferedInputFile example is used to accumulate the contents of the file. This means that it will constantly store and add to the contents of the file as it is being read, allowing for efficient memory usage and faster processing. Option A is incorrect because the FileReader class is responsible for reading data from the file. Option B is incorrect because the InputStreamReader class is responsible for converting bytes to characters. Option D is incorrect because the BufferedReader class is responsible for buffering the file input. Therefore, C is the most accurate option as it describes the main purpose of the StringBuilder class in this example.