Java 实例 使用递归来反转字符串

我们将看到两个程序来反转一个字符串。第一个程序使用递归反转给定的字符串，第二个程序读取用户输入的字符串然后反转它。

示例 1：用于反转字符串的程序

public class JavaExample {    public static void main(String[] args) {        String str = "Welcome to Beginnersbook";        String reversed = reverseString(str);        System.out.println("The reversed string is: " + reversed);    }    public static String reverseString(String str)    {        if (str.isEmpty())            return str;        //Calling Function Recursively        return reverseString(str.substring(1)) + str.charAt(0);    }}

输出：

The reversed string is: koobsrennigeB ot emocleW

示例 2：用于反转用户输入的字符串的程序

import java.util.Scanner;public class JavaExample {    public static void main(String[] args) {        String str;        System.out.println("Enter your username: ");        Scanner scanner = new Scanner(System.in);        str = scanner.nextLine();        scanner.close();        String reversed = reverseString(str);        System.out.println("The reversed string is: " + reversed);    }    public static String reverseString(String str)    {        if (str.isEmpty())            return str;        //Calling Function Recursively        return reverseString(str.substring(1)) + str.charAt(0);    }}

输出：

Enter your username: How are you doing?The reversed string is: ?gniod uoy era woH