在repl.it上反转java中的字符串（忽略已经起作用的代码的第一部分）

Question

嗨，我需要一些代码方面的帮助，我正在尝试反转用户输入的字符串，如果有人有repl.it的经验，请在此处提供代码

import java.util.Scanner;



public class Main {

  public static void main(String[] args) {

    Scanner inp = new Scanner(System.in);
    System.out.println("enter a number");
    int i = inp.nextInt();
    int o =i+i;
    System.out.println(o);
  }
  Scanner inp = new Scanner(System.in);
    System.out.print("In:");
    String word = inp.nextLine();
int counter = word.length();
    for(counter>0){
      System.out.println(word.charAt(counter));
    int counter-1;
  }

    }

这里是一长串错误

退出状态1Main.java:16：错误：预期

System.out.print("In:");

                ^

Main.java:16：错误：类型的非法开始

System.out.print("In:");

                 ^

Main.java:19：错误：类型的非法开始

for(counter>0){

^

Main.java:19：错误：预期

for(counter>0){

           ^

Main.java:19：错误：';'预期

for(counter>0){

            ^

Main.java:19：错误：类型的非法开始

for(counter>0){

             ^

Main.java:19：错误：预期

for(counter>0){

              ^

Main.java:19：错误：';'预期

for(counter>0){

               ^

Main.java:20：错误：类型的非法开始

  System.out.println(word.charAt(counter));

        ^

Main.java:20：错误：';'预期

  System.out.println(word.charAt(counter));

            ^

Main.java:20：错误：方法声明无效；返回类型必填

  System.out.println(word.charAt(counter));

             ^

Main.java:20：错误：预期

  System.out.println(word.charAt(counter));

                                ^

Main.java:20：错误：';'预期

  System.out.println(word.charAt(counter));

                                 ^

Main.java:20：错误：类型的非法开始

  System.out.println(word.charAt(counter));

                                        ^

Main.java:20：错误：预期

  System.out.println(word.charAt(counter));

                                         ^

Main.java:21：错误：';'预期

int counter-1;

           ^

Main.java:24：错误：预期使用类，接口或枚举

}

^

17个错误

Answer 1

public static void main(String [] args) {
    try (Scanner scanner = new Scanner(System.in)) {
        System.out.println("In: ");
        String word = scanner.nextLine();
        System.out.println(new StringBuilder(word).reverse());
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Answer 2

这是固定的最终结果

import java.util.Scanner;

public class Main {

  public static void main(String[] args) {

    Scanner inp = new Scanner(System.in);
    System.out.println("enter a number");
    int i = inp.nextInt();
    int o =i+i;
    System.out.println(o);
  Scanner in = new Scanner(System.in);
  System.out.print("In:");
    String word = in.nextLine();
    //write your code below
    int counter = word.length();
    while(counter>0){
      System.out.print(word.charAt(counter-1));
      counter--;
    }

  }

}

Answer 3

导致此错误的原因是，您将代码置于main方法之外。您要执行的每个代码都必须属于方法public static void main。

这是解决方法：

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner inp = new Scanner(System.in);
        System.out.println("enter a number");
        int i = inp.nextInt();
        int o =i+i;
        System.out.println(o);

        System.out.print("In:");
        String word = inp.nextLine();
        int counter = word.length();
        for(counter>0){
            System.out.println(word.charAt(counter));
            int counter-1;
        }

    }    
}