Couldn't understand this challenge

Question

hello

def recur(n):
if n == 0:
return 0
else:
return n + recur(n -1)
print(recur(3))

the output is 6
how they got 6!?

thank you

Answer 1

it's a recursive function

eventually it lined up to:
recur(3)
3 + recur(2)
2 + recur(1)
1 + recur(0)

this last recur call returns 0

so sum up all the n's as: 3 + 2 + 1 and there you have it ;)

6 it is

Answer 2

recursion takes a bit to get used to
we've all been there ~_~

Answer 3

thank you so much it's new for me.

Answer 4

are you adding the numbers on the left .. or the parenthesis? I'm guessing the former, but better to ask than assume. :) thanks in advance