FINAL EXAM REVIEW
Spring 2015
FINAL EXAM DETAILS
The Final Exam is on Thursday, April 30 at 5:30-7:30 in our regular classroom,
LOV103.
Make sure you have your Test 1 and Test 2 to study from! If you are comfortable with
every question on those tests, you will be halfway there!
The final is cumulative but there is a bit of an emphasis on material after the second
midterm.
CLASSES
Be able to write a class declaration from scratch. Take the following prompt:
Write the declaration of a class called Rectangle. An object of type Rectangle will store information about a
rectangle shape. Specifically, a Rectangle object should store this data:
•
width (an integer)
•
height (an integer)
•
color (a string)
Your class declaration should include these member functions:
•
A constructor that allows the width, height, and color to be passed in as parameters. The color should
default to “red” if not provided.
•
A default constructor with no arguments.
•
A SetDimensions function which accepts two arguments for width and height and sets the member data
to these values if neither argument is negative. Return a Boolean value indicating success or failure.
•
A GetArea function which calculates the area and returns the value as an integer.
•
A RectangleInfo function which displays the width, height, and color to the user.
CLASSES
Note: Constructors are unique! They do not have a
return value and they have a name identical to the
class itself. One constructor is called immediately
after an object is created.
class Rectangle
{
public:
Rectangle();
Rectangle(int w, int h, string c = “red”);
bool SetDimensions(int w, int h);
int GetArea();
void RectangleInfo();
private:
int width;
int height;
string color;
};
Question: What kinds of includes
do I need in the header,
implementation, and driver files?
CLASSES
Note: Constructors are unique! They do not have a
return value and they have a name identical to the
class itself. One constructor is called immediately
after an object is created.
class Rectangle
{
public:
Rectangle();
Rectangle(int w, int h, string c = “red”);
bool SetDimensions(int w, int h);
int GetArea();
void RectangleInfo();
private:
Question: What kinds of includes do I need in the header,
int width;
implementation, and driver files?
int height;
string color;
Header needs <string>.
};
Implementation needs <iostream> and “rect.h”.
Driver needs “rect.h” and <iostream>.
CLASSES
Given this class declaration, which statements are legal inside of main()?
• Rectangle r;
• Rectangle r(5);
• Rectangle r(3, 2);
• Rectangle r(3, 4, “blue”);
• int x = r.GetArea();
• int w = r.width;
• int y = r.RectangleInfo();
CLASSES
Suggestions:
• Review lecture notes on classes.
• Make sure you know the syntax of class declarations and how to define functions for
classes (the “::” operator!).
• Know the difference between public and private – why might we make some things
private?
• Practice creating classes on your own.
• Work hard on the last assignment.
FUNCTIONS
Be able to declare/define functions from scratch.
Write a function called VowelCount, which takes in as parameters: a character array,
the size of the array, and an integer passed by reference. The function should store
the number of times that a vowel appears in the character array in the integer that
was passed by reference. Ensure that the function cannot change the array.
Example: If the array letters is {‘a’, ‘b’, ‘c’, ‘d’, ‘e’, ‘f’}, then the call
VowelCount(letters, 6, x) should store 2 in x (because there are two vowels in the
array).
FUNCTIONS
void VowelCount(const char letters[], int size, int& num_vowels){
int counter = 0;
char temp;
for(int i = 0; i < size; i++){
temp = tolower(letters[i]);
if(temp == ‘a’ || temp == ‘e’ || temp == ‘i’ || temp == ‘o’ || temp == ‘u’)
counter++;
}
num_vowels = counter;
}
FUNCTIONS
Suggestions:
• Know the structure of a function declaration and definition (and know the difference
between these two concepts!).
• Know the different parameter passing modes: by value and by reference. Also, know
how to make an argument to a function “unchangeable”.
• How are arrays passed into a function?
• Practice writing your own functions – make sure you know how to write the functions
from the Midterms.
OUTPUT
Be able to write the output of a code segment. Be aware of every cout statement!
void DoSomething(int x, int& y, char z[] )
{
x = x - 11;
y=y+5;
z[4] = ‘y’;
z[8] = ‘g’;
z[3] = ‘\0’;
}
Note: when printing c-style strings
with the insertion operator, the program
will print until it finds a ‘\0’.
int main()
{
int a = 20, b = 9;
char food[] = “Apple pie”;
DoSomething(a, b, food);
cout << “a = ” << a << “b = ” << b << “\nfood = ” << food << ‘\n’;
}
OUTPUT
Be able to write the output of a code segment. Be aware of every cout statement!
void DoSomething(int x, int& y, char z[] )
{
x = x - 11;
y=y+5;
z[4] = ‘y’;
z[8] = ‘g’;
z[3] = ‘\0’;
}
Output:
a = 20 b = 14
food = App
int main()
{
int a = 20, b = 9;
char food[] = “Apple pie”;
DoSomething(a, b, food);
cout << “a = ” << a << “b = ” << b << “\nfood = ” << food << ‘\n’;
}
OUTPUT
Suggestions:
• Practice evaluating the code segments from the tests.
• Write small pieces of code using the string manipulation functions and I/O
formatting functions and try to “guess” what will pop up on the screen. Run your
program to see if you were right.
OUTPUT WITH STRING OBJECTS
char temp, char str1[20] = “pepper”, str2[20] = “banana”, str3[20] = “kiwi”;
What is the output of the following code segment?
strcat(str3, str2);
cout << str3 << endl;
temp = toupper(str2[2]);
cout << temp << ‘ ’ << strlen(str1) << ‘\n’;
strcpy(str3, “chili”);
strcat(str1, “ ”);
strcat(str2, str1);
strncat(str3, str1, 3);
cout << “str1 = ” << str1 << “ str2 = “ << str2 << “ str3 = ” << str3 << ‘\n’;
OUTPUT WITH STRING OBJECTS
char temp, char str1[20] = “pepper”, str2[20] = “banana”, str3[20] = “kiwi”;
What is the output of the following code segment?
strcat(str3, str2);
Output:
cout << str3 << endl;
kiwibanana
temp = toupper(str2[2]);
N6
cout << temp << ‘ ’ << strlen(str1) << ‘\n’;
str1 = pepper str2 = bananapepper str3 = chilipep
strcpy(str3, “chili”);
strcat(str1, “ ”);
strcat(str2, str1);
strncat(str3, str1, 3);
cout << “str1 = ” << str1 << “ str2 = “ << str2 << “ str3 = ” << str3 << ‘\n’;
EVALUATE CODE SEGMENTS
What is the value of a after the following code segment is executed?
int a, x = 5, y = 3;
a = ++x * y--;
cout << “a is ” << a;
EVALUATE CODE SEGMENTS
What is the value of a after the following code segment is executed?
int a, x = 5, y = 3;
a = ++x * y--;
cout << “a is ” << a;
Output:
a is 18
QUESTIONS?
On Thursday, April 23, we will have a question-and-answer session for the Final. You
do not have to attend if you feel comfortable with the material. I will be in our
classroom for the duration of the class and you may come and go as you like with
questions.
I will not have anything prepared so if you want to review something, you’ll have to
specifically ask about it.