Rayon s and Men Pack Women Socks from Bamboo Quarter s 6 MD Black IxZYqw0A
Hem Summer Jaycargogo Neck Backless 5 Sleeveless Women V Elastic Irregular Dress Neck Backless 5 Elastic Sleeveless Irregular Jaycargogo V Hem Summer Dress Women

Sleeveless 5 Women Hem Elastic Neck Backless V Irregular Summer Dress Jaycargogo w7qEvPq

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