A function to get next fibonacci series

Fibonacci.kt

var hashMap = HashMap<Int, Long>()

private fun fibonacci(i: Long): Long {
    if(hashMap.containsKey(i)) {
        return hashMap[i] ?: 0
    }

    var result: Long = if (i <= 2) 1 else fibonacci(i - 1) + fibonacci(i - 2)

    hashMap[i] = result
    return result
}

private fun nextFibonacci(number: Long) {
    var index = 0L
    var fibonacciNumber = 0L

    try {
        while (fibonacciNumber <= number) {
            fibonacciNumber = fibonacci(index)
            index++
        }
        println(fibonacciNumber)
    } catch (e: Exception) {
        println(0)
    }
}