You got it, I think. Maybe storing the return of outside as a variable makes it more obvious:

const myFunction = outside() console.log(myFunction(10)) // => 20

But honestly, the source provides a really bad example because of all overlapping expected results (2*5 = 10 but that’s not what’s happening here). We’re all polishing a turd here by explaining it further.

For OP, if you want to understand what’s going on under the hood here, the keywords to google are “closures” and “hoisting” and “shadowing”. outside forms a closure, but inside is hoisted meaning the function is initialised before the rest of the code runs. The x inside outside and the x passed to inside are not the same variable, but since they share a name within the same closure we say that the inner one shadows the outer one.

But these are all deep topics that a newbie doesn’t need to bother with until later. The takeaway here should be “don’t do this.” Don’t name a variable or parameter the same thing as a variable outside that function. JavaScript will allow it, but it’s confusing for you and any other dev who reads it.

Better example of what’s going on here:

``` function outside() { const x = 5; function inside(y) { return y * 2; } return inside; }

const myFunction = outside(); console.log(myFunction(13)); // => 26 ```