Women Long BOwith Sequins Dress Backless Prom Bridesmaid Dresses Chiffon Y1wqd1F
Coolred Patterned Two Women Maxi Chinese Pieces Fake Green Linen Style Dress Style Women Maxi Green Patterned Coolred Two Linen Chinese Fake Pieces Dress

Pieces Two Fake Women Dress Chinese Style Patterned Coolred Green Maxi Linen TqPIwwZ

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