CS 1430: Programming in C++

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

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

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]; . . .

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!

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.

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; } };

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; } };

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!

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

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.

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!

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

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

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

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.";

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.";

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; }

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

Schedule Quiz5-5: Due today Lab 7 Quiz7-1: Due Monday Test 2: 60 points Notes 11 - 22 Program 4 Due Thursday, Nov 5

Quiz2 Now