Constructors

on Saturday, 18th of July, 2020

Constructors are used to create objects with pre-determined values for the properties. Constructors come in three flavors: the standard constructors, named constructors, and factory constructors. (Factory constructors are discussed on a different page.)

class Cat {
    String name;
    String color;
    
    // a simple constructor
    Cat(this.name, this.color);

    // named constructors are used to define additional constructors
    // they return a new instance of the class, (but not with a 'return' statement) 
    // usually with some values given defined values.
    Cat.orange(this.name) {
        color = 'Orange';
    }
    
    // this is another named constructor example
    Cat.black(this.name) {
        color = 'Black';
    }
  
    
    String toString() => "Cat: ${this.name}, ${this.color}";
}

void main() {
    print(Cat('nora', 'orange'));
    print(Cat.orange('nora'));
    print(Cat.black('nora'));
    print(Cat.fromJson({'name': 'Nora', 'color':'Orange'}));
}


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