Property in Controller class can't used in the functions which are register in Routes

[zzczzc004]

I want to add a property in the Controller class. Like in the HeroController, I add a 'test' property, and I want to use it in the create function. But when create is invoke by the route, it show [TypeError: Cannot read property 'test' of undefined].

I think it's because typescript is simulate class but Javascript didn't have a class until ES6. I have use c# before and use Javascript and Typescript recently but not full understand it.

class HeroController {

    test = "test";

    create(req: express.Request, res: express.Response): void {
        console.log(this.test);
    }
}

[zzczzc004]

I found I got an incorrect understanding about keywords this before, and solved the problem by change the way of register controller in the Routes. Before: router.post("/heroes", controller.create); After: router.post("/heroes", (req, res) => controller.create(req, res));

[zzczzc004]

I found 'this' in TypeScript is a common problem, here are some useful blog and wiki about understand it and how to avoid it.

[moizKachwala]

glad you got the resolution :)