notNull

Returns a property delegate for a read/write property with a non-null value that is initialized not during object construction time but at a later time. Trying to read the property before the initial value has been assigned results in an exception.

Samples

import kotlin.properties.Delegates
import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   var max: Int by Delegates.notNull()

assertFailsWith<IllegalStateException> { println(max) }

max = 10
assertPrints(max, "10") 
   //sampleEnd
}