Class Diagrams in Object-Oriented Programming

Class Diagrams

• A visual representation of classes and their relationships in an object-oriented program
• Consists of:
  • Classes ( rectangles )
  • Attributes (data members, listed inside the class rectangle)
  • Methods (functions, listed inside the class rectangle)
  • Relationships between classes (lines connecting the classes)
• Types of relationships:
  • Inheritance (arrow pointing to the parent class)
  • Composition (filled diamond shape at the aggregate end)
  • Association (simple line)

Polymorphism

• The ability of an object to take on multiple forms
• Achieved through:
  • Method Overloading (multiple methods with the same name but different parameters)
  • Method Overriding (a subclass provides a different implementation of a method already defined in its superclass)
  • Operator Overloading (defining custom behavior for operators such as +, -, *, /)
• Benefits:
  • Increased flexibility and reusability of code
  • Allows for more accurate modeling of real-world objects and behaviors

Encapsulation

• The idea of bundling data and methods that operate on that data within a single unit (a class)
• Benefits:
  • Data Hiding (protecting data from external interference and misuse)
  • Abstraction (focusing on essential features and hiding irrelevant details)
  • Code Organization (grouping related data and methods together)

Inheritance

• A mechanism for creating a new class (the subclass or derived class) based on an existing class (the superclass or base class)
• The subclass inherits all the attributes and methods of the superclass and can also add new attributes and methods or override the ones inherited from the superclass
• Types of inheritance:
  • Single Inheritance (a subclass inherits from a single superclass)
  • Multiple Inheritance (a subclass inherits from multiple superclasses)
  • Multilevel Inheritance (a subclass inherits from a superclass that itself inherits from another superclass)
• Benefits:
  • Code Reusability (reusing code from the superclass)
  • Hierarchical relationships between classes

Class Diagrams

• Visual representation of classes and their relationships in an object-oriented program
• Composed of classes, attributes, methods, and relationships between classes
• Classes are represented by rectangles
• Attributes are data members listed inside the class rectangle
• Methods are functions listed inside the class rectangle
• Relationships between classes are represented by lines connecting the classes
• Three types of relationships: inheritance, composition, and association
• Inheritance is represented by an arrow pointing to the parent class
• Composition is represented by a filled diamond shape at the aggregate end
• Association is represented by a simple line

Polymorphism

• Ability of an object to take on multiple forms
• Achieved through method overloading, method overriding, and operator overloading
• Method overloading involves multiple methods with the same name but different parameters
• Method overriding involves a subclass providing a different implementation of a method already defined in its superclass
• Operator overloading involves defining custom behavior for operators such as +, -, *, /
• Benefits of polymorphism include increased flexibility and reusability of code, and more accurate modeling of real-world objects and behaviors

Encapsulation

• Idea of bundling data and methods that operate on that data within a single unit (a class)
• Benefits of encapsulation include data hiding, abstraction, and code organization
• Data hiding protects data from external interference and misuse
• Abstraction focuses on essential features and hides irrelevant details
• Code organization involves grouping related data and methods together

Inheritance

• Mechanism for creating a new class (the subclass or derived class) based on an existing class (the superclass or base class)
• Subclass inherits all the attributes and methods of the superclass
• Subclass can also add new attributes and methods or override the ones inherited from the superclass
• Three types of inheritance: single inheritance, multiple inheritance, and multilevel inheritance
• Single inheritance involves a subclass inheriting from a single superclass
• Multiple inheritance involves a subclass inheriting from multiple superclasses
• Multilevel inheritance involves a subclass inheriting from a superclass that itself inherits from another superclass
• Benefits of inheritance include code reusability and hierarchical relationships between classes