Dart OOP - Complete Dart Tutorial

🎯 What is Dart OOP?

Object-Oriented Programming in Dart helps organize code using classes and objects. It makes code reusable, maintainable, and easier to understand by modeling real-world entities and their relationships.


// Simple OOP example in Dart
class Car {
  String brand = 'Toyota';
  
  void start() {
    print('$brand car is starting!');
  }
}

void main() {
  Car myCar = Car();
  myCar.start();
}

Core OOP Principles

📦

Encapsulation

Bundle data and methods together

class BankAccount {
  double _balance = 0; // Private
  
  void deposit(double amount) {
    _balance += amount;
  }
}

🧬

Inheritance

Create new classes from existing ones

class Animal {
  void eat() => print('Eating');
}

class Dog extends Animal {
  void bark() => print('Woof!');
}

🎭

Polymorphism

Same method, different behaviors

class Shape {
  void draw() => print('Drawing shape');
}

class Circle extends Shape {
  void draw() => print('Drawing circle');
}

🔒

Abstraction

Hide complex implementation details

abstract class Vehicle {
  void start(); // Must be implemented
  
  void stop() {
    print('Vehicle stopped');
  }
}

🔹 Basic Class Example

Here's a simple class that demonstrates OOP concepts:

class Student {
  // Properties (attributes)
  String name;
  int age;
  List subjects = [];
  
  // Constructor
  Student(this.name, this.age);
  
  // Methods (behaviors)
  void addSubject(String subject) {
    subjects.add(subject);
    print('$name enrolled in $subject');
  }
  
  void displayInfo() {
    print('Student: $name, Age: $age');
    print('Subjects: ${subjects.join(', ')}');
  }
}

void main() {
  // Creating an object
  Student student1 = Student('Alice', 20);
  student1.addSubject('Math');
  student1.addSubject('Physics');
  student1.displayInfo();
}

Output:

Alice enrolled in Math

Alice enrolled in Physics

Student: Alice, Age: 20

Subjects: Math, Physics

🔹 Why Use OOP in Dart?

Object-Oriented Programming provides several benefits:

Benefits of OOP:

Code Reusability: Write once, use multiple times
Modularity: Break complex problems into smaller parts
Maintainability: Easy to update and modify code
Security: Hide sensitive data using encapsulation
Real-world Modeling: Represent real entities as objects

// Real-world example: Library System
class Book {
  String title;
  String author;
  bool isAvailable = true;
  
  Book(this.title, this.author);
  
  void borrow() {
    if (isAvailable) {
      isAvailable = false;
      print('$title has been borrowed');
    } else {
      print('$title is not available');
    }
  }
  
  void returnBook() {
    isAvailable = true;
    print('$title has been returned');
  }
}

Dart Object-Oriented Programming