Marylin Flip For Cover For S9 Wallet Samsung Samsung Dress Galaxy 8Tq5q1wX
Sleeveless Women Relaxed Comfy Rise Dress Coolred Party Mini As1 High Coolred Sleeveless Relaxed High Party Women Comfy As1 Dress Mini Rise

As1 Comfy High Women Mini Coolred Dress Party Sleeveless Relaxed Rise 6Pqzn

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