capitalize

Common
JVM
JS
Native
1.0
fun String.capitalize(): String

Returns a copy of this string having its first letter titlecased using the rules of the default locale, or the original string if it's empty or already starts with a title case letter.

The title case of a character is usually the same as its upper case with several exceptions. The particular list of characters with the special title case form depends on the underlying platform.

import java.util.Locale
import kotlin.test.*

fun main(args: Array<String>) {
//sampleStart
println("abcd".capitalize()) // Abcd
println("Abcd".capitalize()) // Abcd
//sampleEnd
}
JVM
1.4
fun String.capitalize(locale: Locale): String

Returns a copy of this string having its first letter titlecased using the rules of the specified locale, or the original string if it's empty or already starts with a title case letter.

The title case of a character is usually the same as its upper case with several exceptions. The particular list of characters with the special title case form depends on the underlying platform.