replaceFirstChar
@JvmName
(
"replaceFirstCharWithChar"
)
inline
fun
String
.
replaceFirstChar
(
transform
:
(
Char
)
->
Char
)
:
String
(source)
@JvmName
(
"replaceFirstCharWithCharSequence"
)
inline
fun
String
.
replaceFirstChar
(
transform
:
(
Char
)
->
CharSequence
)
:
String
(source)
Returns a copy of this string having its first character replaced with the result of the specified transform , or the original string if it's empty.
import java.util.Locale
import kotlin.test.*
fun main(args: Array<String>) {
//sampleStart
println("kotlin".replaceFirstChar { it.uppercase() }) // Kotlin
val sentence = "Welcome to Kotlin!"
val words = sentence.split(' ');
println(words.joinToString(separator = "_") { word -> word.replaceFirstChar { it.lowercase() } }) // welcome_to_kotlin!
//sampleEnd
}
Parameters
transform
- function that takes the first character and returns the result of the transform applied to the character.