when

when ( lang ) {
equalIgnoreCase "AR" -> "Arabic"
equalIgnoreCase "EN" -> "English"
equalIgnoreCase "RU" -> "Russian"
}

when {
  lang.equals("AR", true) -> "Arabic"
}

private fun String.expandName(): String =
            when {
                this.equals("AR", true) -> "Arabic"
                this.equals("EN", true) -> "English"
                this.equals("RU", true) -> "Russian"
                else -> this
            }

    @Test
    fun asas() {
        val value: String = "AR"
        assertEquals("Arabic", value.expandName())
    }

when(lang.toUpperCase()) {
  "AR" -> "Arabic"
}

lang.toUpperCase(<http://Locale.US|Locale.US>)