1. Anatomy of a class Part I
CSCE 121
J. Michael Moore
Based on Slides created by Carlos Soto.

2. Classes in C++ User-defined datatypes Data members (aka attributes)
Variables that are instances of a class datatype are called objects
Data members (aka attributes)
Can be any datatype
Including other classes
Member functions (aka methods)
Act with or upon the object used to call the method

3. Visibility Private Public Can only be accessed from within the class
Commonly used for most data members
Default for C++ classes
Public
Can be accessed inside or outside the class
Commonly used for user-facing functions
Make up the class’s interface
Default for C++ structs

4. Class names are capitalized by convention.
Writing a class
class Student { };
Class names are capitalized by convention.

5. Writing a class: public and private member access
class Student { private: // data members and member functions public: // ... };
Class names are capitalized by convention.

6. Writing a class: attributes / data members
class Student { private: string name; int id; double grade; char letterGrade; public: // data members and member functions };

7. Writing a class: mutators and accessors / setters and getters
class Student { private: string name; int id; double grade; char letterGrade; public: string getName (); void setName (string name); // ... };
Note: member functions
are declared, not defined.

8. Writing a class: function definitions/declarations
class Student { string name; // ... public: string getName () { return name; } void setName (string name) { name = name; };
This does not work. Parameter name hides class name.
Which name is which???

9. Writing a class: using ‘implicit’ this parameter
class Student { string name; // ... public: string getName () void setName (string name) };
‘this’ indicates the one that belongs to the class. {
return name; }
this->name = name;
Alternatively you could give
them different names.
Some will add an underscore to the beginning of one of them. E.g. _name

10. Writing a class: function definition outside class definition
class Student { string name; // ... public: string getName (); void setName (string name); }; string Student::getName () { return name; }
Scope Resolution Operator

11. Using a class Declare/define variable just like any other datatype.
class Student { // ... public: string getName(); void setName(string name); }; int main() { Student joe; joe.setName(“Joe Smith”); string name = joe.getName(); }
Declare/define variable just like any other datatype.
Access attributes/methods with
. (dot) operator. Just like using vectors.

12. Classes & Structs: default visibility
class MyClass { // members are private by default }; struct MyStruct { // members are public by default