javascript - ES6 Arrow function: why "this" points differently when used in constructor and object literal?

Question

I know that arrow functions inherit this from enclosing scope. Yet, still can't understand why this in arrow function defined in object literal points to global object, while in constructor to created object. Consider following code:

function Obj() {
  this.show = () => {
    console.log(this);
  };
}
const o = new Obj();
const o2 = {
  show: () => {
    console.log(this);
  }
}

o.show(); // o
o2.show() // window || undefinded

Answer 1

Ok, found the answer, as stated in "Secrets of the javascript ninja":

Arrow functions don't have their own context. Instead, the context is inherited from the function in which they’re defined.

So inside constructor function this === {}. While, when defining object literal this still points to global object or undefined if in strict mode.