Example of programming paradigm

Circle.kt

data class Circle(val radius: Double) {
  fun getArea(): Double {
    return Math.PI * radius * radius
  }
}

fun main(args: Array<String>) {
  val c = Circle(5.0)
  println("The area of the circle is ${c.getArea()}")
}

factorial.c

#include <stdio.h>

int factorial(int n) {
  int result = 1;
  for (int i = 1; i <= n; i++) {
    result *= i;
  }
  return result;
}

int main() {
  int n = 5;
  printf("The factorial of %d is %d\n", n, factorial(n));
  return 0;
}

Functional.kt

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

println("The factorial of 5 is " + factorial(5))