Mouse Butterflies YT14 Grass The Pad Mousepad Pad Mouse Pads Mouse on OwO1qTr
Bodycon Wrapped Back Open Sexy Comfy Women Chest s Black Dress Bandage Cami Club Comfy Cami Sexy Women Open Bandage Bodycon Wrapped Chest s Club Black Dress Back

Bodycon Black Cami Club Women Back Comfy Dress Open Chest s Sexy Wrapped Bandage wqtxnO7R

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