io

[madhu avula]

JQ+ Question ID :971005958690

Which of the following code segments will correctly write the text "FINAL TEXT" to the end of a file "file.txt ?
1. RandomAccessFile raf = new RandomAccessFile("file.txt", "a");
raf.writeChars("FINAL TEXT");
2. RandomAccessFile raf = new RandomAccessFile("file.txt", "rw");
raf.writeChars("FINAL TEXT");
3. RandomAccessFile raf = new RandomAccessFile("file.txt", "a");
raf.seek( raf.length() );
raf.writeChars("FINAL TEXT");
4. RandomAccessFile raf = new RandomAccessFile("file.txt", "rw");
raf.seek( raf.length() );
raf.writeChars("FINAL TEXT");
5. RandomAccessFile raf = new RandomAccessFile("file.txt", "rw");
raf.seek( raf.length() - 1);
raf.writeChars("FINAL TEXT");

According to me the correct answer is 5.
But answer given in jq+ is 4.
anybody please let me know which is correct?
thanks in advance
madhu

[Marilyn de Queiroz]

What happened when you used --
RandomAccessFile raf = new RandomAccessFile("file.txt", "rw");
raf.seek( raf.length() - 1);
raf.writeChars("FINAL TEXT");
??

[madhu avula]

marlin,
i tried both options 4 and 5.
both are printing "FINAL TEXT" at end of file.

thanks in advance.
madhu

[Manfred Leonhardt]

Hi Madhu,
You must not have been looking very closely at the results.
Lets show a simple example. The original file.txt contains the following single line of text:
Madhu Avula
Now we run case number 4:

RandomAccessFile raf = new RandomAccessFile("file.txt", "rw");
raf.seek( raf.length() );
raf.writeChars("FINAL TEXT");

The file now contains the single line of text:
Madhu AvulaFINAL TEXT
So far so good, now we will run the case number 5:

RandomAccessFile raf = new RandomAccessFile("file.txt", "rw");
raf.seek( raf.length()-1 );
raf.writeChars("FINAL TEXT");

The file now contains the single line of text:
Madhu AvulFINAL TEXT
Something is different here ... the comparison between the two is left as a homework assignment for the student.
Now read the question very carefully:

Which of the following code segments will correctly write the text "FINAL TEXT" to the end of a file "file.txt ?

Regards,
Manfred.

[madhu avula]

Hi Manfred,
thank's for u'r explanation.it's very clear.i got it.
thanks a lot
madhu