Dress 7 DaisyFormals Dress lavender Strap Bridesmaid Party Chiffon W BM2454S Wedding Beach xYvAqZx
Dress for Sleeve Rainbow Button Half Casual Women Down Dress Maxi Striped Blue Maxi Striped Down for Women Blue Half Button Rainbow Dress Sleeve Casual Dress

Striped Blue for Maxi Sleeve Dress Casual Rainbow Button Dress Half Women Down wAxq8TR

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