1. CS 1430: Programming in C++

2. Class Constructors class Student { private:
string id, firstName, lastName;
float gpa;
. . .
public:
Student()
Student(string sID)
Student(string first, string last)
Student(string sID, float g)
Student(string sID, string first, string last, float g) };

3. Creating Class Objects
// Must have the default constructor
Student s;
Student s1();
// Creating a Student object by calling
// Student(string first, string last, float g)
Student s2(“Qi”, “Yang”, 2.9);
string first, last;
float myGPA;
cin >> last >> first >> myGPA;
Student s3(first, last, myGPA);

4. Creating Class Objects
// Creating a Student object by calling a constructor
Student s = Student(“Qi”, “Yang”);
// Override data of s
s.Read();
// Creating an object and assign it to s
s = Student(“13579”, “Joe”, “Clifton”, 3.9);
string first, last;
float myGPA;
cin >> last >> first >> myGPA;
s = Student(first, last, myGPA);

5. Array of Objects int numStudents; string id, first, last; float myGPA;
// Must have default constructor
Student s, allStudents[30];
cin >> id >> last >> first >> myGPA;
// Creating an object and assign it to s
s = Student(id, first, last, myGPA);
// Copy s to allStudents[0]
allStudents[0] = s;

6. Array of Objects int numStudents; string id, first, last; float myGPA;
Student s, allStudents[30];
cin >> numStudents;
for (int i = 0; i < numStudents; i ++) {
cin >> id >> last >> first >> myGPA;
s = Student(id, first, last, myGPA);
allStudents[i] = s; }

7. Array of Objects int numStudents; string id, first, last; float myGPA;
Student s, allStudents[30];
cin >> numStudents;
for (int i = 0; i < numStudents; i ++) {
cin >> id >> last >> first >> myGPA;
//s = Student(id, first, last, myGPA);
allStudents[i] = Student(id, first, last, myGPA); }

8. Class StudentList class StudentList { private: int numStudents;
Student students[MAX_SIZE];
public:
void Read()
string id, first, last;
float myGPA;
cin >> numStudents;
for (int i = 0; i < numStudents; i ++)
cin >> id >> last >> first >> myGPA;
allStudents[i] = Student(id, first, last, myGPA); } };

9. Class StudentList class StudentList { private: int numStudents;
Student students[MAX_SIZE];
public:
void Read()
cin >> numStudents;
for (int i = 0; i < numStudents; i ++)
// Assuming class Student has method Read()
allStudents[i].Read(); }
void Write() const
// Print all students one by one };

10. Class Student and StudentList{
private:
. . .
public:
void Read()
void Write() const };
class StudentList

11. Class Student and StudentList{
. . . };
class StudentList
int main()
StudentList cs143_S2;
cs143_S2.Read();
cs143_S2.Write();
return 0; }

12. More Methods for Class StudentList{
private:
int numStudents;
Student students[MAX_SIZE];
public:
. . .
float MaxGPA() const
float max = students[0].GetGPA();
for (int i = 1; i < numStudents; i ++)
if (students[i].GetGPA() > max)
max = students[i].GetGPA();
return max; } };

13. Class Student and StudentList{ };
class StudentList
int main()
StudentList cs143_S2;
float maxGPA;
cs143_S2.Read();
cs143_S2.Write();
maxGPA = cs143_S2.MaxGPA();
cout << “The max GPA for CS143 Section 2 is ”
<< maxGPA;
return 0; }

14. More Methods for Class StudentList{
. . .
public:
float MaxGPA() const
float MinGPA() const
float AverageGPA() const
void GetStats(float& max, float& min, float& avg) const
float gpa;
max = min = avg = students[0].GetGPA();
for (int i = 1; i < numStudents; i ++)
gpa = students[i].GetGPA();
if (gpa > max)
max = gpa;
if (gpa < min)
min = gpa;
avg += gpa; }
avg /= numStudents; };

15. Class Student and StudentList
class StudentList
int main() {
StudentList cs143_S2;
float maxGPA, minGPA, avgGPA;
cs143_S2.Read();
cs143_S2.Write();
cs143_S2.GetStats(maxGPA, minGPA, avgGPA);
cout << “CS143 Section 2” << endl;
cout << “ Max GPA: ” << maxGPA << endl
<< “ Min GPA: ” << minGPA << endl
<< “ Avg GPA: ” << avgGPA;
return 0; }

16. More Methods for Class StudentList{
private:
int numStudents;
Student students[MAX_SIZE];
public:
. . .
Student MaxGPAStudent() const
int index = 0;
for (int i = 1; i < numStudents; i ++)
if (students[i].GetGPA() > students[index].GetGPA())
index = i;
return students[index]; } };

17. Class Student and StudentList{ };
class StudentList
int main()
StudentList cs143_S2;
Student s;
cs143_S2.Read();
cs143_S2.Write();
s = cs143_S2.MaxGPAStudent();
cout << “The student with max GPA for CS143 Section 2 is\n”;
s.Write();
return 0; }

18. More Methods for Class StudentList{
private:
int numStudents;
Student students[MAX_SIZE];
int find(const Student& s) const
for (int i = 0; i < numStudents; i++)
if (students[i].GetFirst() == s.GetFirst() &&
students[i].GetLast() == s.GetLast())
return i;
return -1; }
public:
. . .
void UpdateStudentGPA(const Student& s, float g)
// Need to find where s is in students[] };

19. More Methods for Class StudentList{
private:
int numStudents;
Student students[MAX_SIZE];
int find(const Student& s) const
public:
. . .
bool UpdateStudentGPA(const Student& s, float g)
int index = find(s);
if (index == -1)
return false;
students[index].UpdateGPA(g);
return true; } };

20. Class Student and StudentList
int main() {
StudentList cs143_S2;
Student s;
cs143_S2.Read();
cs143_S2.Write();
s = Student(“Qi”, “Yang”);
if (cs143_S2.UpdateStudentGPA(s, 0.5))
cout << endl << “GPA is updated for ”
<< s.GetFirst() << “ ” << s.GetLast() << ‘.’; }
else
cout << endl << s.GetFirst() << “ ” << s.GetLast()
<< “ is not in CS143 Section 2.”;
return 0;

21. Schedule
Quiz7-4
Lab 9
Program 5
Pairs Sign up Today