isNullOrBlank

inline fun CharSequence?.isNullOrBlank(): Boolean

Returns true if this nullable char sequence is either null or empty or consists solely of whitespace characters.

Samples

import samples.*
import java.util.Locale
import kotlin.test.*
fun main() { 
   //sampleStart 
   fun validateName(name: String?): String {
    if (name.isNullOrBlank()) throw IllegalArgumentException("Name cannot be blank")
    // name is not nullable here anymore due to a smart cast after calling isNullOrBlank
    return name
}

assertPrints(validateName("Adam"), "Adam")
assertFails { validateName(null) }
assertFails { validateName("") }
assertFails { validateName("  \t\n") } 
   //sampleEnd
}