Course Content

C# Basics

## C# Basics

# Practicing Method with Parameters

In this challenge you need to create a new method called `factorial`

which will have one parameter called `n`

of type `int`

. It should calculate the factorial of the passed value `n`

and output the result.

The blueprint of the program is given, fill the missing details to complete the program:

main

- We had done a factorial related exercise in one of the previous sections but to recap, the factorial of a number is the product of all the numbers up till that number.
For-example the factorial of
`5`

is`1 x 2 x 3 x 4 x 5`

which is`120`

, similarly the factorial of`4`

is`24`

. There are two additional rules:

- Factorial of
`0`

is`1`

; - Factorial of a negative number is
`undefined`

so it should output`undefined`

;

- For solving the task, following the following steps:

- Fill in the blank for the
`factorial`

method with appropriate parameter definition. It expects an integer. Figure out what should be the name of the parameter by reading the method's inner code; - If the passed argument is
`0`

, it should show a fixed output which is mentioned in the hints; - The loop should continue up till (including the number) the passed integer. The
`result`

variable should be updated with the product of itself with the loop variable. In short:`result *= i`

; - If the input number is negative (invalid), it should output "undefined".

main

Everything was clear?