val words = arrayOf("hello", "world", "kotlin")
// 从右到左连接所有单词，并添加索引信息
val joinedString = words.reduceRightIndexed { index, word, acc ->
    acc + index + "_ " + word
}
// 输出：连接后的字符串: 2_kotlin 1_world 0_hello
_console.log("连接后的字符串: ", joinedString)