1. CS 1430: Programming in C++

2. Student Data First Name Last Name ID GPA DOB Phone ...
How to store student data in our programs?

3. Store Student Data in Variables
// For one student at a time
float gpa;
string firstName, lastName, id; …

4. Store Students Data in Parallel Arrays
const int MAX_SIZE = 30;
// To keep data for all students
Float gpas[MAX_SIZE];
string firstNames[MAX_SIZE], lastNames[MAX_SIZE],
ids[MAX_SIZE];
. . .

5. C++ Class class Student { string id; string firstName, lastName;
float gpa; };
// Student is a class (data type)!
// By default, all fields are private.
// Class Scope!

6. Create public functions (methods) to access private fields.
C++ Class
class Student {
private:
string id;
string firstName, lastName;
float gpa;
public:
. . . };
Create public functions (methods)
to access private fields.

7. Class Methods class Student { private: string id;
string firstName, lastName;
float gpa;
public:
// Make sure the order is correct.
void Read()
cin >> id >> firstName >> lastName
>> gpa; } };

8. Class Methods class Student { private: string id;
string firstName, lastName;
float gpa;
public:
void Read()
void Print()
cout << endl;
cout << setw(9) << id << setw(20) << firstName
<< setw(20) << lastName << setw(5) << gpa; } };

9. Calling Class Methods Using the dot notation! Student s1;
// Input data into object s1
s1.Read();
// Output data of object s1
s1.Print();
Using the dot notation!

10. Syntax and Style class Student { private: string id;
string firstName, lastName;
float gpa;
public:
void Read()
. . . };
// class, private, public: key word
// Student: Identifier, your choice
// Fields : Declaring variables
// Braces
// Semicolon after }
// Read, Print: class methods (function inside class)
// Indentation

11. Semantics Student is a new data type!
class Student {
private:
string id;
string firstName, lastName;
float gpa;
public:
void Read()
cin >> id >> firstName >> lastName
>> gpa; }
. . . };
Student is a new data type!
It has data fields and methods (functions) on the data.

12. Semantics
class Student {
private:
string id;
string firstName, lastName;
float gpa;
public:
void Read()
cin >> id >> firstName >> lastName
>> gpa; }
. . . };
Data fields have class scope and can be accessed from any class methods!

13. C++ Classes cin >> base;
while ( !cin.eof() && (base < 2 || base > 9) ) {
// display message
cin.ignore(MAX_LINE_SIZE, ‘\n’);
cin >> base: }

14. More Class Methods class Student { private: . . . public:
string getFirstName()
return firstName; }
void setFirstName( string name )
firstName = name; };

15. More Class Methods class Student { private: . . . public:
string getGPA()
return gpa; }
void setGPA( float value )
gpa = value;
void updateGPA( float amount )
gpa += amount; };

16. Calling Class Methods // Comparing two students
if ( s1.getGPA() > s2.getGPA() )
cout << “\nFirst student has higher GPA.";
else if ( s1.getGPA() < s2.getGPA() )
cout << “\nSecond student has higher GPA.";
else
cout << “\nThe two student have the same GPA.";

17. Calling Class Methods // Updating students data s1.setGPA( 2.9 );
s1.updateGPA( 0.5 );
if ( s1.getGPA() > s2.getGPA() )
cout << “\nFirst student has higher GPA.";
else if ( s1.getGPA() < s2.getGPA() )
cout << “\nSecond student has higher GPA.";
else
cout << “\nThe two student have the same GPA.";

18. class Student {
. . . };
int main()
Student s1, s2;
s1.Read();
s2.Read();
s1.Print();
s2.Print();
// Comparing GPA of s1 and s2
s1.updateGPA( 0.5 );
return 0; }

19. //----------------------------------------
// Comment Block
// Includes
// constants
class Student {
. . . };
// Function prototypes
int main()
return 0; }
// Function definitions

20. Schedule Quiz5-5: Due today Lab 7 Quiz7-1: Due Monday
Test 2: 60 points
Notes
Program 4
Due Thursday, Nov 5

21. Quiz2 Now