Java 方法一直给我："cannot find symbol"

Question

我正在编写一个解密程序。我四处张望，但我无法弄清楚是什么给我带来了错误。该代码应该采用用户输入，采用数字（标记为键），然后将字符串中的所有字符移动该数字。任何帮助将不胜感激。

这是我的代码：

import java.util.Scanner;
import java.io.*;

class Assignment3 {

    public static void decipher(int key, String scanInput)
    {
         
          for (int x = 0; x < scanInput.length(); x++) {
            int letterDecode = abc.indexOf(scanInput.charAt(x)) + key;
            deciphered = deciphered + abc.charAt(letterDecode); 
            
            }    
            System.out.println(deciphered);
    
    } 
    
    public static void main(String[] args)
    {
    
      Scanner scan = new scanner(System.in);
      String abc = "abcdefghijklmnopqrstuvdxyzABCDEFGHIJKLMNOPQRSTUPWXYZ";
      String deciphered = "";
      
      
      System.out.println("Please enter your code below");
      String scanInput = scan.nextLine();
      
      System.out.println("Please enter your key (Preferrable from 1-26");
      int key = scan.nextInt();
      
      decipher();        
           
    }
}

这些是错误：

     Assignment3.java:21: error: cannot find symbol
                int letterDecode = abc.indexOf(scanInput.charAt(x)) + key;
                                   ^
      symbol:   variable abc
      location: class Assignment3
    Assignment3.java:22: error: cannot find symbol
                deciphered = deciphered + abc.charAt(letterDecode); 
                ^
      symbol:   variable deciphered
      location: class Assignment3
    Assignment3.java:22: error: cannot find symbol
                deciphered = deciphered + abc.charAt(letterDecode); 
                             ^
      symbol:   variable deciphered
      location: class Assignment3
    Assignment3.java:22: error: cannot find symbol
                deciphered = deciphered + abc.charAt(letterDecode); 
                                          ^
      symbol:   variable abc
      location: class Assignment3
    Assignment3.java:25: error: cannot find symbol
                System.out.println(deciphered);
                                   ^
      symbol:   variable deciphered
      location: class Assignment3
    Assignment3.java:32: error: cannot find symbol
          Scanner scan = new scanner(System.in);
                             ^
      symbol:   class scanner
      location: class Assignment3
    Assignment3.java:43: error: method decipher in class Assignment3 cannot be applied to given types;
          decipher();
          ^
      required: int,String
      found: no arguments
      reason: actual and formal argument lists differ in length
    7 errors

Answer 1

首先你需要在decipher方法中声明abc和deciphered变量。此外，不要忘记在您的方法中传递 key 和 scanInput 变量（主方法的最后一行）。请看下面的例子：

public static void decipher(int key, String scanInput)
{
    String abc = "abcdefghijklmnopqrstuvdxyzABCDEFGHIJKLMNOPQRSTUPWXYZ";
    String deciphered = "";
    for (int x = 0; x < scanInput.length(); x++) {
        int letterDecode = abc.indexOf(scanInput.charAt(x)) + key;
        deciphered = deciphered + abc.charAt(letterDecode);

    }
    System.out.println(deciphered);

}

public static void main(String[] args)
{

    Scanner scan = new Scanner(System.in);
    
    System.out.println("Please enter your code below");
    String scanInput = scan.nextLine();

    System.out.println("Please enter your key (Preferrable from 1-26");
    int key = scan.nextInt();

    decipher(key, scanInput);
}

Java 方法一直给我："cannot find symbol"

Java method keeps giving me: "cannot find symbol"

java

methods

compiler-errors