Black beaded dress White EARTH DRESS 33543 Lara embroidered long PwfW0TAq
Bridal Wedding Women Dresses Strapless White Dress Long Pleated XingMeng for Wedding Dresses for Long Women Pleated Strapless Bridal Dress XingMeng White

Dress Wedding Women XingMeng White for Pleated Strapless Bridal Dresses Long Yww5SqB

A constructor parameter decorator that marks a dependency as optional.

See also

Description

The DI framework provides null if the dependency is not found. For example, the following code allows the possibility of a null result:

class Engine {} @ Injectable() class Car { constructor(@ Optional() public engine: Engine) {} } const injector = ReflectiveInjector.resolveAndCreate([Car]); expect(injector.get(Car).engine).toBeNull();
      
      class Engine {}

@Injectable()
class Car {
  constructor(@Optional() public engine: Engine) {}
}

const injector = ReflectiveInjector.resolveAndCreate([Car]);
expect(injector.get(Car).engine).toBeNull();
    

Options