When working with Angular Components written in TypeScript, it is possible to declare a class member (variable) as a parameter of the constructor. I am curious about the reason for doing so.
To clarify, take a look at the examples below. Both achieve the same result.
- The first example follows the classic approach of defining a private member using dependency injection (common in most object-oriented languages).
- The second example, if I understand correctly, showcases a specificity of TypeScript.
export class HeroListComponent implements OnInit {
// declaring a private member
private heroService:HeroService;
// constructor signature
constructor(service:HeroService) {
// assigning the private member
this.heroService = service;
}
}
export class HeroListComponent implements OnInit {
// private member declared within the constructor signature
constructor(private heroService:HeroService) { }
}
In my view, the first syntax is more straightforward and comprehensible for those unfamiliar with TypeScript.
Therefore, I am questioning whether there is a specific rationale, aside from brevity (which becomes negligible once minified/obfuscated), for opting for the latter syntax. Thank you.