kotlin factorial

To calculate the factorial of a number in Kotlin, you can use a recursive function. Here is an example:

fun factorial(n: Int): Int {
    return if (n == 0) {
        1
    } else {
        n * factorial(n - 1)
    }
}

fun main() {
    val number = 5
    val result = factorial(number)
    println("The factorial of $number is $result.")
}

Explanation of each step: 1. We define a function called factorial that takes an integer n as input and returns an integer as output. 2. Inside the function, we use an if statement to check if n is equal to 0. If it is, we return 1 because the factorial of 0 is 1. 3. If n is not equal to 0, we use recursion to calculate the factorial. We multiply n with the factorial of n-1 and return the result. 4. In the main function, we declare a variable called number and assign it the value of 5. 5. We call the factorial function with number as the argument and assign the result to a variable called result. 6. Finally, we use println to display the calculated factorial by concatenating the values of number and result.