Kotlin Essential Training

Chapter 4 - Section 4

	fun main(args: Array<String>) {
		var nullValue:String? = null
		println(nullValue)

		val l:Int? = nullValue?.length
		println("Length is $l")

		if (l == null) {
			println("Length is null")
		}

		val message = if (l != null) {
			"Length: $l"
		} else {
			"l is null"
		}
		println(message)

		val l2 = l ?: -1
		println("The value of l2 is $l2")

		try {
			val l3 = l!!
			println("The value of l3 is $l3")
		} catch (e: KotlinNullPointerException) {
			println("l3 is null")
		}

	}