Nullable Types

Use ? and ?: to handle missing values.

NullableTypes.kt

fun main() {
    val nickname: String? = 
    val display = nickname ?: "guest"
    val length = display.length

    println("display=$display")
    println("length=$length")
}

fun main() {
    val nickname: String? = 
    val display = nickname ?: "guest"
    val length = display.length

    println("display=$display")
    println("length=$length")
}

fun main() {
    val nickname: String? = 
    val display = nickname ?: "guest"
    val length = display.length

    println("display=$display")
    println("length=$length")
}

null A nullable type can hold either a value or `null`.