Null Safety Patterns

Safe Calls

Use ?. to read a member only when a value is present.

Safe Calls

SafeCalls.kt 
fun main() {
    val word: String? = 
    val hasText = word?.isNotEmpty() == true
    val report = if (hasText) "has text" else "no text"

    println("word=${word ?: "none"}")
    println(report)
}

fun main() {
    val word: String? = 
    val hasText = word?.isNotEmpty() == true
    val report = if (hasText) "has text" else "no text"

    println("word=${word ?: "none"}")
    println(report)
}

fun main() {
    val word: String? = 
    val hasText = word?.isNotEmpty() == true
    val report = if (hasText) "has text" else "no text"

    println("word=${word ?: "none"}")
    println(report)
}
safe-call The safe-call operator returns `null` instead of calling through a missing value.