Decimal to roman numeral converter in kotlin

Kotlin program for Decimal to roman numeral converter. Here mentioned other language solution.

//  Kotlin program for
//  Conversion from Decimal to roman number
class Perform {
    // Display roman value of n
    fun show(n : Int) : Unit
    {
        when (n)
         {
            // Test Cases
            1  -> print("I");
            4  -> print("IV");
            5  -> print("V"); 
            9  -> print("IX");
            10 -> print("X");
            40 -> print("XL");
            50 -> print("L");
            90 -> print("XC");
            100-> print("C");
            400-> print("CD");
            500-> print("D");  
            900-> print("DM");
            1000-> print("M");
        }
    }
    fun select(number : Long, 
               collection : Array<Int>, 
               size : Int) : Long
    {
        var n : Int = 1;
        var i : Int = 0;
        while (i < size)
        {
            if (number >= collection[i])
            {
                n = collection[i];
            }
            else
            {
                break;
            }
            i += 1;
        }
        this.show(n);
        // Reduce the value of number
        return number - n;
    }
    fun roman(n : Long) : Unit
    {
      	var number = n;
        if (number <= 0)
        {
            // When is not a natural number
            return;
        }
        // Base case collection
        val collection : Array<Int> =
        arrayOf(1, 4, 5, 9, 10, 40, 50,
         90, 100, 400, 500, 900, 1000);
        // Get the size of collection
        val size : Int = collection.count();
        print(" " + n + " : ");
        while (number > 0)
        {
            number = this.select(number, collection, size);
        }
        println();
    }
}
fun main(args : Array<String>) : Unit
{
    val task : Perform = Perform();
    // Test Case
    task.roman(10);
    task.roman(18);
    task.roman(189);
    task.roman(604);
    task.roman(982);
    task.roman(3000);
}

Output

 10 : X
 18 : XVIII
 189 : CLXXXIX
 604 : DCIV
 982 : DMLXXXII
 3000 : MMM