How would we use looping to calculate factorials , while loop?

Question

I wrote a code so that I can calculate factorials using loop methods in python. But when I runned my program(provided below) i behaves like an infinite loop. Help me to get it out.

a = int(input('n...'))

while a >= 0:
      a *= a - 1
      print(a)

Answer 1

The problem in your code is that you are updating the same variable a while check if its greater than 0 in while loop condition. If a is multiplied by any non-zero number, your code would always enter an infinite loop. Following is how you can correct it:

a = int(input('n...'))
factorial = 1

while a > 0:
    factorial *= a
    a -= 1

print(f'The factorial is: {factorial}')