TypeWtf

foo.ts

 export MyClass {

    private foo: string = "hello";

    public addHandler() {
        window.addEventListener("resize", this.logResize);
    }

    public logResize() {
        console.log(this); // Expected: MyClass | Actual: Window
        console.log(foo);  // Expected: "hello" | Actual: Undefined
    }
  
  //fixed
    public logResize = () => {
        console.log(this); // Expected: MyClass | Actual: Window
        console.log(foo);  // Expected: "hello" | Actual: Undefined
    }
}