Question

Factorial Calculation Write a Python program that prompts the user to enter a positive integer and calculates its factorial using a while loop. The program should then display the result to the user.

The expected requirements from your program are listed below:
- Your program must use a while loop to calculate the factorial of the user input.
- Your program must perform the multiplication operation and check the current number being multiplied.
- Your program should display the result of the factorial operation to the user in a user-friendly message.
Hints
- You can use the input() function to prompt the user to enter a number.
- You can use the int() function to convert the user input from string type to an integer type.
- You can use a while loop with a condition that checks if the current number is less than or equal to the user input.
- You can use one variable to store the current result of the multiplication operation and another variable for the current number being multiplied.
- You can multiply the running product by the current number inside the loop and then increment the current number by 1.
- You can display the factorial to the user in a user-friendly message using the print() function.

Answer 1

To calculate the factorial of a positive integer using a while loop in Python, you can prompt the user for input and then use a while loop to perform the multiplication operation and check the current number being multiplied. The program should display the result of the factorial operation to the user.

Step-by-step explanation:

To calculate the factorial of a positive integer using a while loop in Python, you can follow these steps:

1. Prompt the user to enter a positive integer using the input() function and convert it to an integer using the int() function.
2. Initialize two variables: one to store the current result of the multiplication operation (let's call it factorial and set it to 1), and another to store the current number being multiplied (let's call it num and set it to the user input).
3. While num is greater than 1, multiply factorial by num, and decrement num by 1.
4. After the while loop, factorial will contain the factorial of the user input. Display the result to the user using the print() function in a friendly message.

Here's an example of the program:

i=input('Enter a positive integer: ')
num = int(i)
factorial = 1
while num > 1:
factorial *= num
num -= 1
print('The factorial of', i, 'is', factorial)