Calling Constructors and Methods of Parent Class

In Dart, you can call the parent class’s constructors and methods from derived classes using the super keyword. Here are examples of both:

Calling Parent Constructors

To call a parent class’s constructor, you use the super keyword in the derived class’s constructor. Here’s how you can do it:

class Animal {
  String name;

  Animal(this.name) {
    print("$name is an animal.");
  }
}

class Dog extends Animal {
  String breed;

  Dog(String name, this.breed) : super(name) {
    print("$name is a $breed.");
  }
}

void main() {
  var dog = Dog("Buddy", "Golden Retriever");
}

In this example:

• The Animal class has a constructor that takes a name parameter.
• The Dog class extends Animal and has its own constructor that takes name and breed parameters.
• The super(name) call in the Dog class constructor calls the Animal class constructor, passing the name parameter.

Calling Parent Methods

To call a parent class’s method, you also use the super keyword. Here’s an example:

class Animal {
  void eat() {
    print("Animal is eating");
  }
}

class Dog extends Animal {
  void eat() {
    super.eat(); // Calling the parent class method
    print("Dog is eating");
  }

  void bark() {
    print("Dog is barking");
  }
}

void main() {
  var dog = Dog();
  dog.eat();  // Calls both the Animal and Dog eat methods
  dog.bark();
}

In this example:

• The Animal class has an eat method.
• The Dog class overrides the eat method and calls the parent class’s eat method using super.eat() before executing its own code.

By using super, you can ensure that your derived classes can access and extend the behavior of their base classes effectively.