Answer:
The given JavaScript code defines two functions, `f` and `n`, and then calls the `f` function. Let's break down what each part of the code does:
1. `var a = 1;` - This declares a variable `a` and assigns it the value 1. This is a global variable.
2. `function f() { ... }` - This defines a function `f`. Inside `f`, there's another function `n` defined.
3. `var a = 2;` - Inside the `f` function, there's a declaration of a local variable `a` with the value 2. This local variable shadows the global variable `a`.
4. `n();` - This calls the `n` function from within the `f` function.
5. `function n() { (a); }` - This defines the `n` function, which contains the expression `(a)`. Note that there are parentheses around `a`, but it's not doing anything here.
Now, when you call `f();`, it executes the `f` function. Within the `f` function, `n();` is called. Inside the `n` function, `(a);` is evaluated. Since `a` is declared locally within the `f` function, it uses the local variable `a`, which has a value of 2.
So, the code will display nothing (undefined) because the expression `(a);` doesn't have any effect, and there are no `console.log` statements or output operations in the code.