Cruiize V 4 Womens Black Sleeve Sexy Sequins 3 Deep Short Slim Club Dress xxTwSr
Purple Women Dress Hollow Traditional Cheongsam Coolred Premium Split Slim Out Split Women Cheongsam Hollow Purple Out Coolred Dress Traditional Slim Premium

Out Premium Coolred Women Cheongsam Slim Split Traditional Dress Purple Hollow HwqPXqEa

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