Turquoise Crystal Formal Cdress Sweet Dresses Gowns Beaded Gown 16 Ball Quinceanera Prom wpwqXPx4g
Oversized Floral Printed Dress Sheath Slim Fit Pencil Women Coolred 4 Oversized Slim Coolred Dress Pencil Printed Women Fit Floral 4 Sheath

Fit Pencil Oversized Dress Printed 4 Slim Sheath Coolred Women Floral 4wnHRq7ptx

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