Angular2 cast a json result to an interface

Question

Using Angular2 and typescript, I have JSON returned from a webApi and I need to get it into an array of a certain type. I can\'t figure out how to cast the json to the inte

Answer 1

You can do a type assertion to the interface you are expecting on the object created by JSON.parse.

 this.http.get('http://localhost:4200/').subscribe((value: Response) => {
    let hero = value.json();
  });

However this will not result in any errors if the server sends you bad objects because of 2 reasons.

At compile time the transpiler does not know what the server will send.

At runtime all type information is erased since everything gets compiled to javascript.