Name:
(as it would appear on official course roster)
Umail address:	@umail.ucsb.edu	section 9am or 10:30am
Optional: name you wish to be called if different from name above.
Optional: name of "homework buddy" (leaving this blank signifies "I worked alone"

h10: Homework 10

ready?	assigned	due	points
true	Thu 10/27 02:00PM	Tue 11/01 02:00PM

You may collaborate on this homework with AT MOST one person, an optional "homework buddy".

MAY ONLY BE TURNED IN IN THE LECTURE/LAB LISTED ABOVE AS THE DUE DATE,
OR IF APPLICABLE, SUBMITTED ON GRADESCOPE. There is NO MAKEUP for missed assignments;
in place of that, we drop the three lowest scores (if you have zeros, those are the three lowest scores.)

Please:

No Staples.
No Paperclips.
No folded down corners.

Read Chapter 5.4 thru 6.1. (If you do not have a copy of the textbook yet, there is one on reserve at the library under “COMP000-STAFF - Permanent Reserve”).

PLEASE MARK YOUR HOMEWORK CLEARLY, REGARDLESS OF IF YOU WRITE IT OUT IN INK OR PENCIL!
FOR BEST RESULTS, PRINT THIS PAGE AS A PDF, THEN PRINT THE PDF

(6 pts) Why would a programmer use a driver program? What about a stub?
(4 pts) What is the “Fundamental Rule for Testing Functions” actually telling us?
(4 pts) When debugging a program, explain why randomly changing code is generally not a good idea.

4.(2 pts) Show where you would insert an assert statement in this code in order to make sure that you would not get a run error:

#include <iostream>
#include <cassert>
using namespace std;

void foo(int x, int y) {
  y = 5 / x;
  cout << "Result = " << y << endl;
}

int main() {
  int a, b;
  cin >> a >> b;  
  foo(a, b);
  return 0;
}

5.(12 pts) What member functions do the following in C++11? Show the usual parameters/arguments, if any:

Opens a file in ofstream classes:

Opens a file in ifstream classes:

Closes a file in ofstream classes:

Checks to see if opening an input file failed in ifstream classes:

Returns the position in the input file where you want to start reading in ifstream classes:

Returns the position in the output sequence in ofstream classes:

6.(12pts) When users run the following program: (a) What do they see on their screen? and (b) What do they see in the file myData.txt?

#include <iostream>
#include <fstream>
int main () {
	using namespace std;
	ofstream out_stream;
	int x = 55, y =66;
	
	out_stream.open("myData.txt");
	for (int i = 0; i < 5; i++)
		out_stream << x << y << endl;
	out_stream.close();
	
	cout << "File is written";
	return 0;
}