在此程序中，您將學習在Kotlin中使用遞歸循環(huán)來反轉(zhuǎn)給定的句子。
fun main(args: Array<String>) {
val sentence = "Go work"
val reversed = reverse(sentence)
println("倒過來的句子是: $reversed")
}
fun reverse(sentence: String): String {
if (sentence.isEmpty())
return sentence
return reverse(sentence.substring(1)) + sentence[0]
}運行該程序時，輸出為：
倒過來的句子是：KROW OG
在上面的程序中，我們有一個遞歸函數(shù)reverse()。
| Iteration | reverse() | substring() | reversedString |
|---|---|---|---|
| 1 | reverse("Go work") | "o Work" | result + "G" |
| 2 | reverse("o Work") | " Work" | result + "o" + "G" |
| 3 | reverse(" Work") | "Work" | result + " " + "o" + "G" |
| 4 | reverse("Work") | "ork" | result + "W" + " " + "o" + "G" |
| 5 | reverse("ork") | "rk" | result + "o" + "W" + " " + "o" + "G" |
| 6 | reverse("rk") | "k" | result + "r" + "o" + "W" + " " + "o" + "G" |
| 7 | reverse("k") | "" | result + "k" + "r" + "o" + "W" + " " + "o" + "G" |
| Final | reverse("") | - | "" + "k" + "r" + "o" + "W" + " " + "o" + "G" = "kroW oG" |
這是等效的Java代碼：顛倒句子的Java程序