UNIT IV
NOTE Part(A) material posted separately in Google Classroom,Part(B) material 3 topics given here
and remaining topics is the first 6 experiments in your record itself is the notes
(A) User interface design: Characteristics of good user interface design, Basic concepts, Types of
user interfaces, component-based GUI development, A user interface Design Methodology
(B)Unified Modeling Language: Overview of Object-oriented concepts, Unified Modeling Language,
UML diagrams, use case model class diagrams, Interaction diagrams, Activity diagrams, state chart
diagrams
1. Overview of Object-Oriented Concepts
Object-Oriented Programming (OOP) is a programming paradigm based on the concept of objects,
which contain both data and behavior. It makes software modular, reusable, and easier to maintain.
Key Concepts
1. Object
o Real-world entity with attributes (data) and methods (behavior).
o Example: A Car object has color, speed (data), and drive(), brake() (behavior).
2. Class
o A blueprint or template used to create objects.
o Defines common attributes and methods.
o Example: Class Car → Objects: Car1, Car2, Car3.
3. Encapsulation
o Wrapping data and methods into a single unit (class).
o Provides data hiding using access modifiers.
o Example: Bank account details are private, but accessible via deposit() and
withdraw().
4. Abstraction
o Showing only essential details and hiding implementation.
o Example: ATM → user sees options (Withdraw, Deposit) but not internal code.
5. Inheritance
o Mechanism by which a new class (child) acquires features of an existing class
(parent).
o Promotes code reusability.
o Example: Class Dog inherits from Animal.
6. Polymorphism
o Same method name behaves differently based on context.
o Types:
▪ Compile-time (Overloading)
▪ Run-time (Overriding)
o Example: draw() → draws a circle in Circle class, square in Square class.
7. Message Passing
o Objects communicate by sending messages (method calls).
o Example: Student object sends borrowBook() message to Library object.
8. Dynamic Binding
o Method execution is decided at runtime.
o Example: animal.speak() → decides at runtime whether Dog’s bark() or Cat’s meow()
is called.
2. Unified Modeling Language (UML)
Definition
• UML is a standard modeling language for visualizing, specifying, constructing, and
documenting software systems.
• Developed by Grady Booch, Ivar Jacobson, James Rumbaugh (Rational Software, 1990s).
Purpose
• To create a blueprint for software systems.
• Helps developers, testers, and stakeholders understand system design.
• Provides a common language for communication in software engineering.
UML Building Blocks
1. Things → Class, Object, Use Case, Node, etc.
2. Relationships → Association, Aggregation, Composition, Dependency, Inheritance.
3. Diagrams → Visual representation of the system.
Advantages
• Standardized (globally accepted).
• Simplifies complex systems into visual models.
• Improves team communication.
• Bridges gap between requirements, design, and coding.
3. UML Diagrams
UML provides 14 diagrams categorized into Structural and Behavioral diagrams.
A. Structural Diagrams (show what the system contains)
1. Class Diagram
o Shows classes, attributes, methods, and relationships.
o Example: Student class → attributes: rollNo, name; methods: study(), attendClass().
2. Object Diagram
o Snapshot of objects and their relationships at a specific time.
3. Component Diagram
o Shows organization and dependencies among components (modules).
4. Deployment Diagram
o Shows physical deployment of software (servers, devices, databases).
5. Package Diagram
o Groups related elements (like folders in a project).
B. Behavioral Diagrams (show how the system behaves)
1. Use Case Diagram
o Shows interaction between actors (users) and the system.
o Example: In Library System → Student borrows book, Librarian manages book.
2. Sequence Diagram
o Shows order of messages exchanged between objects over time.
3. Collaboration/Communication Diagram
o Shows interactions between objects and their relationships.
4. Activity Diagram
o Represents workflow/step-by-step process.
o Example: Login → Validate → Dashboard → Logout.
5. State Chart Diagram
o Shows states of an object and transitions.
o Example: Book → Available → Issued → Returned.
6. Interaction Overview Diagram
o Combines activity + sequence diagrams.
7. Timing Diagram
o Focuses on object behavior across time.
REMAING TOPICS ARE 1-6 EXPERIMENTS IN SE RECORD
