1. +
Lecture 1 – Introduction to
C++ Classes (Part 4)
TTTK1924 – Program Design and Problem
Solving

2. +
Part 4
Data Abstraction and Classes

3. +
Data Abstraction
 Separationof data logical properties from
data implementation details
 Users are given the abstract representation
of data, while the implementation details are
hidden

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Abstract Data Types (ADT)
 Structured data types that apply data abstraction
concept – data types that separate the logical
properties from the implementation details
 An ADT usually has 3 things:
 Type name (name of ADT)
 Domain – set of values belonging to the ADT
 Set of operations – operations that can be done to the
values in ADT (can be used by others)

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Abstract Data Type - Examples
An ADT that handles time:
 Type name : clockType
 Domain : the values of a clock in the form of
hours, minutes, and seconds
 Set of Operations :
 Set the time
 Returns the time
 Increment the time by one second
 Increment the time by one minute
 Increment the time by one hour
 Compare the two times to see whether they are equal

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Abstract Data Type - Examples
An ADT that handles a list of items:
 Type name : listType
 Domain : a collection of items, for example an array of 100
integers
 Set of Operations :
 Check to see whether the list is empty
 Check to see whether the list is full
 Search the list for a given item
 Delete an item from the list
 Insert an item into the list
 Sort the list
 Destroy the list
 Print the items of the list

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Implementation of ADT
 Obviously,classes class listType {
public:
can be used to bool isEmptyList() const;
define an ADT bool is FullList() const;
int search( int item) const;
void insert(int item);
void remove(int item);
void destroyList();
void printList() const;
listType();
private:
int list[100];
int length;
};

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References:
 D.S. Malik (2012). C++ Programming: Program Design
Including Data Structures (5th ed), Thomson Course
Technology.
 Chapter 11 – Classes and Data Abstraction