# Kotlin program: Calculate the factorial of a given number

## Kotlin Basic: Exercise-8 with Solution

Write a Kotlin program to find the factorial of a given number.

Sample Solution:

Kotlin Code:

``````fun main() {
val number = 5
val factorial = calculateFactorial(number)
println("Factorial of \$number: \$factorial")
}

fun calculateFactorial(number: Int): Long {
return if (number == 0 || number == 1) {
1
} else {
var result = 1L
for (i in 2..number) {
result *= i
}
result
}
}
```
```

Sample Output:

```Factorial of 5: 120
```

Explanation:

In the above exercise,

• Inside the "main()" function, a variable named 'number' is declared and assigned a value of 5.
• The calculateFactorial() function is then called with the number as an argument, and the result is stored in a variable named factorial.
• Finally, the result is printed using string interpolation in the println() statement: "Factorial of \$number: \$factorial".

In the calculateFactorial() function,

• The function takes an integer number as a parameter and returns the factorial as a Long value.
• Inside the function, an if statement checks if the number is equal to 0 or 1. If it is, the function returns 1 because the factorial of 0 and 1 is 1.
• If the number is greater than 1, the function initializes a variable result with 1L, indicating the starting value for the factorial calculation.
• A for loop is used, starting from 2 (as the factorial calculation starts from 2) and continuing until number. In each iteration, the result is multiplied by i and assigned back to the result.
• Finally, the calculated factorial is returned.

Kotlin Editor:

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

﻿