Student case study

Example of converting a UML Class diagram to C++ class

UML Class Diagram

where

• vis = visibility (+ for public, - for private)
• attribute = data member (aka field)
• operation = method (or constructor)

Note:

• The arg list is a list of parameter types (e.g., int, double, String); parameter names are not included in the UML class diagram
• Methods that don’t return a value (i.e. void methods) should give a return type of void
• Class (i.e. static) methods and fields are indicated by underlining
• Constant (i.e. final) fields are indicated via naming convention: constants should be in ALL_CAPS

Example: Student UML Class diagram

Corresponding C++ Class

class Student {
    char *name;
    const int ROLL_NO;
    float gpa;
    static int noOfStudents;
public:
    Student(char *, int, float);
    Student(const Student &);
    ~Student();
    void setName(char *);
    void setGpa(float);
    int getROLL_NO() const;
    char * getName() const;
    float getGpa() const;
    static int getTotalStudent();
};
/*private static member cannot be accessed outside the class except for initialization*/
int Student::noOfStudents = 0;
/* Overloaded constructor with default values assigned using member initializer list*/
Student::Student(char *aName = "", int aRollNo = 0, float aGPA = 0.0) : name(aName), ROLL_NO(aRollNo), gpa(aGPA) {
 noOfStudents++;
}
/* Copy constructor with deep copy for pointer members*/
Student::Student(const Student &obj) : ROLL_NO(obj.ROLL_NO), gpa(obj.gpa) {
    int len = strlen(obj.name);
    name = new char[len + 1];
    strcpy_s(name, len + 1, obj.name);
    noOfStudents++;
}
/* Destructor*/
Student::~Student() {
    noOfStudents--;
}
void Student::setName(char * aName) {
 strcpy_s(name, strlen(aName), aName);
}
void Student::setGpa(float aGPA) {
    if (aGPA < 0.0) {
        gpa = 0.0;
    }
    else
    {
        gpa = aGPA;
    }
}
int Student::getROLL_NO()const {
    return ROLL_NO;
}
char * Student::getName() const {
    return name;
}
float Student::getGpa() const {
    return gpa;
}
int Student::getTotalStudent() {
    return noOfStudents;
}