Is this a right statement for Closure?

Question

Quote from Stoyan Stefanov's Object-Oriented JavaScript (page 84):

If you're at point a, you're inside the global space. If you're at point b, which is inside the space of the function F, then you have access to the global space and to the F-space. If you're at point c, which is inside the function N, then you can access the global space, the F-space and the N-space You cannot reach from a to b, because b is invisible outside F. But you can get from c to b if you want, or from N to b. The interesting thing—the closure—happens when somehow N breaks out of F and ends up in the global space."

I think the bold sentence above should be changed to "If you're at point c, which is inside the function N, then you can access the global space and the N-space " (the F-space shouldn't be contained, because the point c only has access to N-space and the global scope G. ).

Am I right? thanks.

Answer 1

No, I think what it's saying is that N is a function that has been returned from function F, and therefore has access (through a closure) to variable b which was declared inside F. For example (live example):

function F() {
    var b = 10;
    return function () {
        console.log(b);
    };      
}

var N = F(); //N is a reference to the anonymous function returned from F

N(); //logs '10' because we still have access to b (because of the closure)