s Underwear Women Sleepwear Babydoll Nightwear New White String Lace G XL Lingerie White Dress XL d11nv
Sequin Fuchsia Homecoming Open Prom Two Short Back Beaded Party 2017 Cocktail Piece Gown Chupeng Dress Sequin Piece Beaded Fuchsia Open Gown Short Homecoming Party 2017 Dress Prom Cocktail Chupeng Back Two

Two Dress Back Sequin Cocktail Fuchsia Party Chupeng 2017 Piece Prom Gown Homecoming Beaded Short Open dw0wqTxz1

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