Kotlin program to find the factorial of a number using recursion

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In this program, you will learn to use recursive functions in Kotlin to find and display the factorial of a number.

The factorial of a positive number n is given by the following formula:

factorial of n (n!) =　1　*　2　*　3　*　4　*　...　*　n

The factorial of a negative number does not exist. The factorial of 0 is1.

In this example, you will learn to use recursion to find the factorial of a number. Visit this page to learn how to find the factorial of a number using a loop. Factorial.

Example: Using recursive factorial

fun main(args: Array<String>) {
　　　　val num =　6
　　　　val factorial = multiplyNumbers(num)
　　　　println("$num's factorial = $factorial")
}
fun multiplyNumbers(num: Int): Long {
　　　　if (num >=　1)
　　　　　　　　return num　*　multiplyNumbers(num　-　1)
　　　　else
　　　　　　　　return　1
}

When running the program, the output is:

　6　factorial =　720

Initially, call multiplyNumbers() from the main() function and pass6is passed as a parameter.

because6is greater than or equal to1, so6multiplied by the result of multiplyNumbers(), where5 (num -1). Because it is called from the same function, it is a recursive call.
In each recursive call, the value of the parameter num is reduced1, until num is less than1. When the value of num is less than1There is no recursive call when

Each recursive call returns to us:

6　*　5　*　4　*　3　*　2　*　1　*　1　(for 0) =　720

The equivalent Java code is as follows:Java Program to Find Factorial Using Recursion

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