Scala program to find Factorial of a number

Given a number N, the task is to calculate factorial of N.

In mathematics, the factorial of a positive integer N is the product of all positive integers less than or equal to N. The recursive formula to calculate factorial of a given positive integer N is

N! = N * ( N -1 )! 
N! = 1 if N = 1 or N = 0

Factorial of a number

Examples:

Input : N = 3 
Output : 6

Input : N = 5
Output : 120

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Method 1 : Iterative Way
In this method, we will use a loop to iterate over the sequence of numbers to get the factorial.
Below is the implementation of above approach
Example :

// Scala Program to calculate 
// Factorial of a number 
  
// Creating object 
object GFG 
{ 
    // Iterative way to calculate 
    // factorial  
    def factorial(n: Int): Int = { 
          
        var f = 1
        for(i <- 1 to n) 
        { 
            f = f * i; 
        } 
          
        return f 
    } 
  
    // Driver Code 
    def main(args: Array[String])  
    { 
        println(factorial(5)) 
    } 
  
} 

Output :

Method 2 : Use of Recursion
In this method, Recursive formula N! = N * (N -1) ! is used to calculate the factorial of the given number.
Below is the implementation of above approach.
Example :

// Scala Program to calculate Factorial 
// of a number using recursion 
  
// Creating object 
object GFG 
{ 
    // Function to calculate 
    // factorial using Recursive  
    // formula (i.e N! = N * N-1 !) 
    def factorial(n: Int): Int =
    { 
        if (n == 0)  
            return 1
        else
            return n * factorial(n-1) 
    } 
  
    // Driver Code 
    def main(args: Array[String])  
    { 
        println(factorial(5)) 
    } 
} 

Output :

My Personal Notes

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

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