Kotlin1.8.0

fun main() {
        val str = "Hello, World!"
        val upperCaseStr = str.uppercase(Locale.getDefault())
        val lowerCaseStr = str.lowercase(Locale.getDefault())
    
        println("Original String: $str")
        println("Uppercase String: $upperCaseStr")
        println("Lowercase String: $lowerCaseStr")
    
        val char = 'a'
        val upperCaseChar = char.uppercaseChar()
        val lowerCaseChar = char.lowercaseChar()
    
        println("Original Char: $char")
        println("Uppercase Char: $upperCaseChar")
        println("Lowercase Char: $lowerCaseChar")
    }