How this code works

Question

please help me with this code
https://code.sololearn.com/cU07sz0ELOx2/?ref=app

Answer 1

Okay, I'll try to explain as best as I can.

Notice on line 1 that we have `x=0` as parameter for function `f`. That means `x` is an optional parameter. It defaults to 0 whenever we call `f` without passing any arguments.

Line 2 isn't doing anything in this program. You can remove it and you'll still get the same output.

On lines 3 and 4, the function `g` is defined as an inner function inside function `f`. It takes a parameter `y` and prints it.

Then on line 5 we print `x`.

The tricky part is understanding what line 6 is doing. Function `f` is returning `g`. That can seem like a strange concept, but yes, functions can return other functions. (this is pretty common when programming in a functional paradigm)

On line 7 you are calling `f` without passing any arguments, as evidenced by the empty parenthesis. Thus we know that `x` is set to 0, which is its default value.
Since `f` returns `g`, what line 7 is doing is passing (1) as argument to function `g` after it is returned from `f`.

I hope this helps clearing your doubts.
If you still have questions, feel free to ask!

Answer 2

Which part of it you don't understand?

Answer 3

the output of f()(1)
is 1 for y or y should equals x

Answer 4

Thanks a lot Eduarda
i understood it because of you