The scope of the ARROW function __ function

Scope of the Arrow function

The arrow function scope is bound to the context of the parent.
Test Cases:

var obj = {
    id:1, show
    : () => {
       console.log (this.id)
    }
}
obj.show ()

Output: undefined
In this case the show function is the arrow function, so this is bound to this in the parent, which is a top-level object in the browser, this points to the Window object, and the window does not have a property ID, so the output undefined

Test Case 2:

var obj = {
    id:1,
    show:function () {return
        () => {
            console.log (this.id)
}}}
obj.show () ()

Output: 1
In this case, the arrow function is an anonymous function whose parent scope is the show function, so the arrow function binds to the scope of the show function, which points to the object that calls the show function, that is, the id attribute in the Obj,obj, and the value is 1, so the output 1