Exam 1z0-829 topic 1 question 17 discussion

Correct answer is F

Buffer only contains [0, 1, 2, 3, 4, 5, 6, 7] In second iteration, in.read(buffer) becomes "-1" . How is the answer F "0123456789234567" ? I ran the program & see only 01234567 in output file.

Correct answer is F Buffer already contains 01234567 and we have 89 left so next time it will replace 0 with 8 and 1 with 9. As there is no data left so it will write 89234567.

package q17; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; public class Q17 { public static void main(String[] args) throws Exception { char[] buffer = new char[8]; int count = 0; try (FileReader in = new FileReader("D:\\in.txt"); FileWriter out = new FileWriter("D:\\out.txt")) { while ((count = in.read(buffer)) != -1) { out.write(buffer); } } // catch (FileNotFoundException e) { // throw new RuntimeException(e); // } catch (IOException e) { // throw new RuntimeException(e); // } } } // Result: // 0123456789234567

Correct option is F, because the buffer is of size 8. Therefore, it can only read 8 characters at a time. First 8 digits in F are correct and the entire thing is of length 16. Although the first 8 digits in B and E are correct, the entire length doesn't add it. Doesn't make sense that the buffer first reads 8 chars, then 6 more in B or 7 more in E.

why is the right option F?

right option is F

the right option is F. 0123456789234567