Save ArrayList to SharedPreferences

Question

I have an ArrayList with custom objects. Each custom object contains a variety of strings and numbers. I need the array to stick around even if the user leaves

Answer 1

Also with Kotlin:

fun SharedPreferences.Editor.putIntegerArrayList(key: String, list: ArrayList?): SharedPreferences.Editor {
    putString(key, list?.joinToString(",") ?: "")
    return this
}

fun SharedPreferences.getIntegerArrayList(key: String, defValue: ArrayList?): ArrayList? {
    val value = getString(key, null)
    if (value.isNullOrBlank())
        return defValue
    return ArrayList (value.split(",").map { it.toInt() }) 
}