Class Constructorsclass 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)

Student(const Student& s)

};

1

Creating Class Objects// Must have the default constructorStudent 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;

// Creating a Student object by calling// Student(string first, string last, float g)Student s3(first, last, myGPA);

2

Creating Class Objects// Works even without default constructorStudent s = Student(“Qi”, “Yang”);

// Override data of ss.Read();

// Creating an object and assign it to ss = Student(“13579”, “Joe”, “Clifton”, 3.9);

string first, last;float myGPA;

cin >> last >> first >> myGPA;

// Creating an object and assign it to ss = Student(first, last, myGPA);

3

Array of Objects

int numStudents;string first, last;float myGPA;

// Must have default constructorStudent s, allStudents[30];

cin >> last >> first >> myGPA;

// Creating an object and assign it to ss = Student(first, last, myGPA);

// Copy s to allStudents[0]allStudents[0] = s;

4

Array of Objectsint numStudents;string first, last;float myGPA;

Student s, allStudents[30];

cin >> numStudents;

for (int i = 0; i < numStudents; i ++){ cin >> last >> first >> myGPA;

s = Student(first, last, myGPA);

allStudents[i] = s;}

5

Array of Objectsint numStudents;string first, last;float myGPA;

Student s, allStudents[30];

cin >> numStudents;

for (int i = 0; i < numStudents; i ++){ cin >> last >> first >> myGPA;

//s = Student(first, last, myGPA);

allStudents[i] = Student(first, last, myGPA);}

6

Class StudentListclass StudentList{private: int numStudents; Student students[MAX_SIZE];

public: void Read() { string first, last; float myGPA;

cin >> numStudents; for (int i = 0; i < numStudents; i ++) { cin >> last >> first >> myGPA; allStudents[i] = Student(first, last, myGPA); } }}; 7

Class StudentListclass 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 }}; 8

Class Student and StudentListclass Student

{

private:

. . .

public:

void Read()

void Write() const

};

class StudentList{private: . . .public: void Read() void Write() const};

9

Class Student and StudentListclass Student

{

. . .

};class StudentList{ . . .};

int main(){ StudentList CS143_S2;

CS143_S2.Read();

CS143_S2.Write(); . . . return 0;}

10

More Methods for Class StudentListclass StudentList{private: int numStudents; Student students[MAX_SIZE];

public: . . . float MaxGPA() const { float max = students[0]; for (int i = 1; i < numStudents; i ++) if (students[i].GetGPA() > max) max = students[i].GetGPA();

return max; }

};11

Class Student and StudentListclass Student

{

};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;} 12

More Methods for Class StudentListclass 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; }}; 13

Class Student and StudentListclass Student

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;}

14

More Methods for Class StudentListclass 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]; }

};15

Class Student and StudentListclass Student

{

};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;} 16

More Methods for Class StudentListclass 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[] }

};17

More Methods for Class StudentListclass 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; }

}; 18

Class Student and StudentListint 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() << ‘.’; CS143_S2.Write(); } else cout << endl << s.GetFirst() << “ ” << s.GetLast() << “ is not in CS143 Section 2.”;

return 0;} 19

Schedule

• Lab 9: Grace Next Wednesday

• Program 5

Pairs Today

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