Asymmetrical Blue Spaghetti s Strapless Dress Strap Women Day Summer CASF SzqYTY
Stylish Chemises Womens Floral Dress White Print Jaycargogo Boho Sexy Dress Print Jaycargogo Chemises Stylish White Womens Sexy Boho Floral

White Dress Womens Boho Chemises Jaycargogo Stylish Sexy Print Floral UxO6F7q

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