Neck V Womens Ruffle Mini Jaycargogo Yellow Spaghetti Dress Straps Wrap WIqW4g
Long Sleeve Dress Bodycon Pencil Sexy Turtleneck Tight ALAIX Stretchy Midi Grey Women Women Long Pencil Grey Turtleneck Stretchy Dress ALAIX Midi Bodycon Tight Sexy Sleeve

ALAIX Sleeve Women Long Grey Stretchy Turtleneck Pencil Bodycon Midi Dress Sexy Tight IxIHwBr

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