Angular: "Unexpected token. A constructor, method, accessor or property was expected"

Question

I wonder why I get this compile error if I declare variable with var or let keywords? I mean, this goes well:

export class AppComponent {

    refreshClickStream$: any;

    constructor(){
    }

While this brings the error:

export class AppComponent {

    var refreshClickStream$: any;

    constructor(){
    }

Answer 1

Inside a class, TypeScript doesn't permit the declaration of class members with

• var
• let
• const (you can use readonly on the property)

Further, inside of a class ALSO you'll be prohibited from declarating functions with

• function

So you want this.

export class AppComponent {

  a: string = "foo";
  b: string = "bar";


  foo(): void { }

  constructor(){
  }

}

Not,

export class AppComponent {

  var a: string = "foo";
  let b: string = "bar";


  function foo(): void { }

  constructor(){
  }

}