Calculate Factorial using While loop in R

R Programming: Control Structure Exercise-2 with Solution

Write a R program that creates while loop to calculate the factorial of a given number.

Sample Solution :

R Programming Code :

# Function to calculate the factorial of a given number
calculate_factorial <- function(n) {
    # Initialize variables
    fact <- 1
    i <- 1
    
    # Check if the entered number is negative
    if (n < 0) {
        print("Factorial is not defined for negative numbers.")
    } else if (n == 0) { # Check if the entered number is 0
        print("Factorial of 0 is 1.")
    } else { # Calculate factorial using a while loop
        while (i <= n) {
            fact <- fact * i
            i <- i + 1
        }
        # Return the factorial of the entered number
        return(fact)
    }
}

# Call the function to calculate the factorial of a given number
number <- 5 # Example: Calculate factorial of 5
factorial_result <- calculate_factorial(number)

# Print the factorial result
cat("Factorial of", number, "is", factorial_result, ".\n")

Output:

Factorial of 5 is 120                  

Explatnaion:

In the exercise above,

• calculate_factorial Function:
• This function calculates the factorial of a given number 'n'.
• It initializes variables 'fact' and 'i' to 1, where 'fact' will store the factorial result and i is a counter for the loop.
• The function first checks if the given number 'n' is negative. If so, it prints a message stating that factorial is not defined for negative numbers.
• If n is not negative, the function then checks if 'n' is equal to 0. If so, it prints a message stating that the factorial of 0 is 1.
• If n is positive, the function enters a while loop where it calculates the factorial iteratively by multiplying 'fact' with 'i' until 'i' reaches 'n'.
• After the loop, the function returns the calculated factorial value.
• Main Code:
• Outside the function, a number (in this case, 5) is assigned to the variable 'number', representing the number whose factorial needs to be calculated.
• The "calculate_factorial()" function is then called with the 'number' as an argument, and the result is stored in the variable 'factorial_result'.
• Finally, the result is printed to the console using 'cat'.

R Programming Code Editor:

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