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fun main() { // Non-nullable string var name: String = "Alice" // name = null // Compile error! // Nullable string var nullableName: String? = "Bob" nullableName = null // OK // Safe call operator ?. val length = nullableName?.length // null if nullableName is null println("Length: $length") // Elvis operator ?: (provide default) val displayName = nullableName ?: "Anonymous" println(displayName) // Not-null assertion !! (throws exception if null) val nonNullable = nullableName!! // throws if null — use carefully // let for null-safe blocks nullableName?.let { n -> println("Name is not null: $n") } ?: println("Name is null") // Smart cast after null check if (nullableName != null) { println(nullableName.length) // auto-cast to String } }
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