Fit BURLADY Patchwork Dress Pat4 Women Belt Flare A Line Sleeveless s Retro Floral nFaOwxR8qF
Easter Kids Bowknots Frames black Glasses Black Bunny Glitter Fancy Dress Ears Decoration Bowknots Black black Frames Glasses Decoration Dress Fancy Glitter Kids Ears Bunny Easter

Fancy Black Ears Kids Easter Dress Frames Decoration Bunny Glasses Glitter Bowknots black R7UZq5w

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