angular - Why use abstract class instead of interface if no methods are implemented -


angular2 in file core/src/metadata/lifecycle_hooks.ts declares class abstract

export abstract class oninit { abstract ngoninit(): void; }

why not declare interface since doesn't have implementation?

interfaces don't exist in java-script; so, presumably, using abstract classes (that don't have member implementations) useful way have "contract" have real type @ run time. 1 possible use dependency injection.


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