inline fun <T : Any> checkNotNull(value: T?): T
Throws an IllegalStateException if the value is null. Otherwise returns the not null value.
import kotlin.test.*
fun main(args: Array<String>) {
//sampleStart
var someState: String? = null
fun getStateValue(): String {
val state = checkNotNull(someState) { "State must be set beforehand" }
check(state.isNotEmpty()) { "State must be non-empty" }
// ...
return state
}
// getStateValue() // will fail with IllegalStateException
someState = ""
// getStateValue() // will fail with IllegalStateException
someState = "non-empty-state"
println(getStateValue()) // non-empty-state
//sampleEnd
}inline fun <T : Any> checkNotNull( value: T?, lazyMessage: () -> Any ): T
Throws an IllegalStateException with the result of calling lazyMessage if the value is null. Otherwise returns the not null value.
import kotlin.test.*
fun main(args: Array<String>) {
//sampleStart
var someState: String? = null
fun getStateValue(): String {
val state = checkNotNull(someState) { "State must be set beforehand" }
check(state.isNotEmpty()) { "State must be non-empty" }
// ...
return state
}
// getStateValue() // will fail with IllegalStateException
someState = ""
// getStateValue() // will fail with IllegalStateException
someState = "non-empty-state"
println(getStateValue()) // non-empty-state
//sampleEnd
}
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Licensed under the Apache License, Version 2.0.
https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/check-not-null.html