Inheritance

Inheritance

About

• Inheritance enables code reuse through parent-child relationships.
• Dart uses single inheritance (one superclass per class).
• Supports method overriding and super calls.
• Fundamental to object-oriented design.

Main Topics

1. Basic Inheritance

   • Definition: Creating child classes with extends.
   • Example:

     class Animal {
       void eat() => print('Eating');
     }
     class Dog extends Animal {} // Inherits eat()

2. Super Constructor

   • Definition: Initializing parent class.
   • Example:

     class Animal {
       String name;
       Animal(this.name);
     }
     class Dog extends Animal {
       Dog(super.name); // Super constructor
     }

3. Method Overriding

   • Definition: Customizing inherited behavior.
   • Example:

     class Dog extends Animal {
       @override
       void eat() => print('Dog eating');
     }

4. Super Calls

   • Definition: Accessing parent implementations.
   • Example:

     void eat() {
       super.eat(); // Parent's eat()
       print('Additional behavior');
     }

How to Use

• Extend: Use extends for basic inheritance
• Initialize: Chain constructors with super()
• Override: Annotate with @override
• Access: Use super for parent members

How It Works

• Hierarchy: Single chain of superclasses
• Lookup: Child methods shadow parent methods
• Construction: Parent initialized before child
• Polymorphism: Child instances as parent types

Example Session:

void main() {
  Animal myDog = Dog(); // Polymorphism
  myDog.eat(); // Calls overridden method
}

Conclusion

Inheritance in Dart provides controlled code reuse while maintaining type safety through method overriding and super calls, forming the backbone of object-oriented design patterns.