Object-Oriented Programming (OOP)

classDiagram
    class Animal {
        +String name
        +int age
        +breathe() void
        +speak() String
    }
    class Dog {
        +String breed
        +bark() void
        +speak() String
    }
    class Cat {
        +bool isIndoor
        +purr() void
        +speak() String
    }
    class BankAccount {
        -float balance
        -String owner
        +getBalance() float
        +deposit(amount) void
        +withdraw(amount) void
    }
    class Shape {
        <<abstract>>
        +area() float
    }
    class Circle {
        +float radius
        +area() float
    }
    class Rectangle {
        +float width
        +float height
        +area() float
    }

    Animal <|-- Dog : Inheritance
    Animal <|-- Cat : Inheritance
    Shape <|-- Circle : Abstraction
    Shape <|-- Rectangle : Abstraction

    style Animal fill:#1a1f2b,stroke:#7c4dff,color:#fff
    style Dog fill:#12161f,stroke:#ff4081,color:#fff
    style Cat fill:#12161f,stroke:#1de9b6,color:#fff
    style BankAccount fill:#1a1f2b,stroke:#7c4dff,color:#fff
    style Shape fill:#0d1117,stroke:#00e5ff,color:#aaa
    style Circle fill:#12161f,stroke:#00e5ff,color:#fff
    style Rectangle fill:#12161f,stroke:#ff4081,color:#fff