Da Salwar Ethnic Indian Anarkali Women Facioun Yellow Kameez Partywear Traditonal Designer qRwqSHxF
Back Short Sequin Piece Cocktail Party Two Beaded Homecoming Dress 2017 Gown Open Prom Chupeng Fuchsia Back Prom Short Two Dress Fuchsia 2017 Chupeng Homecoming Open Sequin Party Cocktail Beaded Gown Piece

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