Java字符串逆序方法的示例分析

public class test_2_13 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        String a = "123456";

        String one = "";
        String two = "";

        // 方法一：
        for (int i = 0; i < a.length(); i++) {
            one += a.substring(a.length() - 1 - i, a.length() - i);
        }

        // 方法二：
        StringBuffer stringBuffer = new StringBuffer(a);
        two = stringBuffer.reverse().toString();

        System.out.println("方法一输出效果:" + one);
        System.out.println("方法二输出效果:" + two);

    }

}

I am a student

nowcoder

import java.util.*;

public class Main {

    private String reverse(String str) {
        StringBuilder res = new StringBuilder(str);
        return res.reverse().toString();
    }

    public Main() {
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            String str = in.nextLine();
            String res = reverse(str);
            System.out.println(res);
        }
   }

    public static void main(String[] args) 
    {
        Main solution = new Main();
    } 
}