Question

1. Suppose you wrote a program that reads data from cin. You are now required to reimplement it so that you can read data from a file. You are considering the following changes.

I. Declare an ifstream variable in_file

II. Replace all occurrences of cin with in_file

III. Replace all occurrences of > > and get_line with the appropriate operations for ifstream objects

What changes do you need to make?

		I, II, and III
		II and III
		I and III
		I and II

2. What is the output of the following code snippet?

cout << setw(2) << setfill('0') << 9;

		209
		09
		009
		9

QUESTION 3

1. What does the following code snippet do for a file of unknown size?

   int i = 0;

   ifstream in_file;

   string mystring;

   in_file.open("test.txt");

   while (getline(in_file, mystring))

   {

      i++;

   }

   cout << i << endl;

   		Counts the number of digits in the file
   		Counts the number of words in the file
   		Counts the number of lines in the file
   		Counts the number of characters in the file

5 points   

QUESTION 4

1. Consider the following code snippet:

   1. int main()

   2. {

   3.    char rd;

   4.    ifstream read_file;

   5.    read_file.open("C:\network.txt");

   6.    while (read_file.get(rd))

   7.    {

   8.       cout << rd << endl;

   9.    }

   10.   return 0;

   11. }

   Which of the following statements describes the problem with this code snippet?

   		The program contains an infinite loop.
   		There is a syntax error in line 6.
   		Line 5 does not open the file C:\network.txt.
   		The variable read_file is never assigned a value.

5 points   

QUESTION 5

1. Assuming that "out_file" is an ofstream object, what is the correct way of opening a file "Employees.txt" for writing?

   		out_Employees.open(Employees.txt);
   		out_file(Employees.txt);
   		out_file.open("Employees.txt");
   		out_file("Employees.txt");

QUESTION 6

1. The command line argument argc has a value of 4. What does this mean?

   		In fact argc must be less than 4.
   		There are three command line arguments stored as character strings that are pointed to by the elements of argv[1], argv[2], and argv[3].
   		There are three command line arguments stored as character strings that are pointed to by the elements of argv[0], argv[1], and argv[2].
   		There are three command line arguments stored as elements of argv[1], argv[2], andargv[3].

QUESTION 7

1. Which of the following is the correct way to call the open function on an ofstream object called writestr?

   		writestr.open("File", ".txt")
   		writestr.open("File.txt", "write")
   		writestr.open("File.txt")
   		writestr.open()

QUESTION 8

1. Suppose you wrote a program that writes data using cout. You are now required to implement it so that you can write data to a file. You are considering the following changes.

   I. Declare an ofstream variable out_file

   II. Replace all occurrences of cout with out_file

   III. Replace all occurrences of < < and put_line with the appropriate operations for ofstream objects

   What changes do you need to make?

   		I, II, and III
   		II and III
   		I and III
   		I and II

question 9

1. To receive command line arguments at run-time, which of the following options represents the correct way to define the main function?

   		int main(int* argc, char argv)
   		int main(int argc[], char* argv)
   		int main(int argc, char argv[])
   		int main(int argc, char* argv[])

QUESTION 10

1. Which of the following function calls can be used to get the current position for reading from a random access file?

   		strm.seekg(position)
   		strm.tellg()
   		strm.tellg(position)
   		strm.tellp()

Answer 1

1.
Option D: I and II only.

2.
09 Option B

3.
C. Counts the number of lines in the file

4.
A. The program contains an infinite loop.

5.
C. out_file.open("Employees.txt");

6.
B. There are three command line arguments stored as character strings that are pointed to by the elements of argv[1], argv[2], and argv[3].

7.
C. writestr.open("File.txt")

8.
D.      I and II

9.
D. int main(int argc, char* argv[])

10.
B. strm.tellg()