Kotlin, ArrayList<String> to String comma delimited and viceversa

convert.kt

fun ArrayListStringToStringComma(arrayList: ArrayList<String>):String{
        var result = ""
        for (i in arrayList.indices) {
            if (i >= 1 && i <= arrayList.size-1) result += ","            
            result += arrayList[i]
        }
        return result
    }


    // The opposite of previous
 
fun StringCommaToArrayListString(listString: String ):ArrayList<String>{
        val result = ArrayList<String>()
        for (w in listString.trim(' ').split(","))
            if (w.isNotEmpty()) result.add(w)
        return result
    }

fun main(args: Array<String>) {
    val arr = ArrayList<String>()
    arr.add("cane")
    arr.add("gatto")
    arr.add("topo")
    arr.add("leone")
    val res: String = ArrayListStringToStringComma(arr)
    println("from arr to string : $res")
    val ARR = StringCommaToArrayListString(res)
    
    for(i in ARR){
        println("from string to arr : ${i}")
    }
    
    
}