簡單的Java加密/解密 - （錯誤：意外的類型||必需：變量找到：值）

Question

我試圖幫助一個同事解碼來自他的朋友的一封信，並且他厭倦了自己做數學。我把它作爲一個嘗試使用Java來幫助他在計算機進行數學運算時加快解密速度的機會。我最初試圖做一次5個角色的塊，但我的陣列是一團糟，他認爲他希望一次完成一個角色。

下面是我的代碼：

import java.io.*; 
class CharlieEncryption 
{ 
    public static void main(String args[]) throws IOException 
    { 
     CharlieEncryption app; 
     app = new CharlieEncryption(); 
     app.appMain(); 
    } 

    BufferedReader stdin; 
    String inString; 
    String encrypt; 
    String decrypt; 

    String[] alphabet = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","Y","X","Z"}; 
    String letter; 
    int letter_code = 0; 
    int number_code = 0; 
    int letter_num = 0; 
    int finish_letter_num = 0; 
    String finish_letter; 

    // appMain module (Call all modules here) 
    public void appMain() throws IOException 
    { 
     Input(); 
     Mode(); 

     if(encrypt.equals("Y")) 
     { 
      Encrypt(); 
      Output(); 
     } 
     else 
     { 
      Decrypt(); 
      Output(); 
     } 
    } 
    //Module to recieve Input 
    void Input() throws IOException 
    { 
     //Requesting Input 
      System.out.print("Please input character"); 
      letter = stdin.readLine(); 
     //Converting Letter to Number 
      for(int j = 0; j < 25; j++) 
      { 
       if(letter.equals(alphabet[j])) 
       { 
        letter_num = j; 
       } 
      } 

     //Requesting Input for Code 
      System.out.println("Please input code for the character"); 
      inString = stdin.readLine(); 
      number_code = Integer.parseInt(inString);    
    } 

    //Module to ask if user wants to encrypt or decrypt 
    void Mode() throws IOException 
    { 
     System.out.println("Would you like to encrypt? Y or N"); 
     encrypt = stdin.readLine(); 

     if(encrypt.equals("N")) 
     { 
      System.out.println("Would you like to decrypt? Y or N"); 
      decrypt = stdin.readLine(); 
     } 
    } 
    //Module to Encrypt Text 
    void Encrypt() 
    { 
      (letter_num) + (number_code) = finish_letter_num; 
     //Converting the finished number to a letter 
     for(int i = 0; i < 25; i++) 
     { 
      if(finish_letter_num == i) 
      { 
       finish_letter = alphabet[i]; 
      } 
     }   
    } 
    //Module to Decrypt Text 
    void Decrypt() 
    { 
      (letter_num) - (number_code) = finish_letter_num; 
     //Converting the finished number to a letter 
     for(int i = 0; i < 25; i++) 
     { 
      if(finish_letter_num == i) 
      { 
       finish_letter = alphabet[i]; 
      } 
     } 
    } 
    //Module to Output Encrypted Text OR Decrypted Text 
    void Output()throws IOException 
    { 
      System.out.println("Result" + finish_letter); 
    } 

} 

下面是錯誤的：

CharlieEncryption.java:78: error: unexpected type 
      (letter_num) + (number_code) = finish_letter_num; 
         ^
     required: variable 
     found: value 
    CharlieEncryption.java:91: error: unexpected type 
      (letter_num) - (number_code) = finish_letter_num; 
         ^
     required: variable 
     found: value 
    2 errors 

試圖讀取所有這些其他人的這種錯誤的問題只是做我的頭不疼，因爲我把握不住他們首先遇到了問題。

Answer 1

嘗試

finish_letter_num = (letter_num) + (number_code); 

，而不是

(letter_num) + (number_code) = finish_letter_num; 

嘗試

(letter_num) - (number_code) = finish_letter_num; 

，而不是

finish_letter_num = (letter_num) - (number_code); 

浩pe這就是你需要的全部