Factorial in Python

Question

I am trying to define a function that returns factorial of an integer.
This program is working perfectly fine, but I have one confusion, the answer should be 20 rather than 120. Because this line of code
return x * factorial(x - 1)
shows multiply x with x-1. If I enter x = 5 then x-1 would be 4, so the answer should be 20 not 120. Why this line of code is multiplying x with x-1 till x becomes 0. there isn't any loop running.

here are my codes
def factorial(x):
if x == 0:
return 1
else:
return x * factorial(x - 1)

print(factorial(5))

Answer 1

Mr. Faisal, How the number is keep decreasing till 0 even there isn't any loop running? It should only be decreased till one number according to code.

Answer 2

There may not be an explicit statement being called to create a loop (ie. while, for, etc.), calling the function while x does not equal 0 will technically create its own loop that will repeat itself until x equals 0.

Hope this helped!

Answer 3

Well, not exactly. What you're doing is calling the function within that same function with the variable x being decreased by 1. This goes on until it reaches 0, multiplying itself by the previous number after every iteration.

Answer 4

Lazy people like me will use imports

https://code.sololearn.com/cu00VM8khFtr/?ref=app