Question

QUESTION 6

1. To determine whether a file was opened successfully, the program can use the fstream function:

   Hint: google

   		fail()
   		open()
   		close()
   		eof()

10 points   

QUESTION 7

1. Which of the following are correct ways to end a loop using a test for end-of-file?

   (Two correct answers)

   		inStream.get(next); while(!inStream.eof( )) { cout << next; inStream.get(next); }
   		while(inStream->next)   { cout << next; }
   		inStream.get(next) while(!eof(inStream)) { cout << next; inStream.get(next); }
   		while(inStream >> next)   cout << next;

10 points   

QUESTION 8

1. Which statement is incorrect?

   		cin is an input stream
   		An output stream flows from your program to somewhere outside the program, either to a file or to some device such as the screen
   		An input stream is a stream of data flowing from your program, either to a file, or to the keyboard
   		A stream is a flow of data into or out of your program

10 points   

QUESTION 9

1. Which of the following sets of statements will set floating point output to the stream outStream to fixed point with set 3 places of decimals?

   (Two correct answers)

   		outStream.setf(ios::fixed); outStream.setf(ios::showpoint); outStream.precision(2);
   		outStream.setf(ios::fixed | ios::showpoint); outStream << setprecision(2);
   		outStream << setflag(ios::fixed); outStream << setflag(ios::showpoint); outStream << setprecision(2);
   		outStream.flags(ios::fixed); outStream.flags(ios::showpoint); outStream.precision(2);

10 points   

QUESTION 10

1. Which statement is incorrect?

   		A file is automatically closed when a program terminates, so there is never a need to close a file
   		The flush function copies the file buffer to the file on the file medium (disk, etc)
   		When you use the open member function to tie a file name to a file stream, the file name is called the external file name, the program refers to the file by the stream variable used to open the file
   		When you write ifstream inStream; inStream.open("infile.dat"); the file infile.dat must be located in the directory where the program is being run

Answer 1

Answer 6: fail()

Explanation: fail() function used to identify whether file is opened successfully. open is used for opening a file, close is used for closing a file and eof() is used for checking eof file.

Answer 7: Correct answer is a, d.

Explanation: You can iterate over file till eof() is reached. You move to next token using .get function.

Also file pointer can be used as reading next token from the file till eof.

Answer 8: C

Explanation: Incorrect answer was C. Input Stream is is always coming inside from file or keyboard.

Others were correct sentence. Cin is input stream. Output stream flows out from your program. Stream is flow of data in and out of the program.

Answer 9: a, b

Explanation: fixed and showpoint can be applied to output stream using setf separately and within the same setf using | operator. Then setprecision is sued to set the precision to 2 decimal point.

Answer 10: A

Explanation: When program terminates , file does not close automatically and file handle will remain open which corrupt the file. So you have to close the file explicitly.