Trim White Neck Stitching Package Solid Lace Hip Coolred Halter Dresses Women YqPWBw
Plus White Black Polka Dress Retro Pinup Flirty Size Rockabilly Dot Black Plus Polka Flirty Retro White Dot Dress Rockabilly Pinup Size

Rockabilly Dot Size Dress Plus White Polka Pinup Black Flirty Retro x778A

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