每當我調試此代碼時，我都會收到「下標超出範圍錯誤」。有人能幫我指出錯誤或錯誤嗎？

Question

我檢查了我所有的字符串和數組。沒有什麼看起來不對我。我的包括陳述可能是問題。也許我錯過了一個。我是一個新手程序員。所以我無能爲力，爲什麼這段代碼不起作用。它看起來是正確的，應該絕對有效。

#include<iostream> 
#include<cstdlib> 
#include<ctime> 
#include<fstream> 
#include<string> 
using namespace std; 

int main() 
{ 
     int i; 
     char response; 
     char answers[20]; 
     char uresponse[20]; 
     int score=0; 


     srand(time(0)); 
     int test_num = rand() % 2+1; 
//  cout << test_num << endl; 
     if (test_num == 1) 
     { 
       string line; 
       ifstream myfile ("form1.txt"); 
       getline (myfile,line); 
//    cout<< line<<endl; 
       for (int i = 0; i <= 19; i++) 
       { 
         answers[i] = line[i*2]; 
//      cout<<answers[i]<<endl; 
       } 
       getline (myfile,line); 

        if (myfile.is_open()) 
        { 
          int x = 0; 
         while (myfile.good()) 
         { 
          char answers[20]; 
           string line; 
           getline (myfile,line); 
//        cout<< line << endl; 
           if(line == "") 
           { 
             cout << "Enter answer: "; 
             cin >> response; 
             if(response == 'a', 'A' || response == 'b', 'B' || response == 'c', 'C' || response == 'd', 'D') 
             { 
               response = response; 
             } 
             else 
             { 
               cout << "ERROR. You must enter A, B, C, or D. Please re-enter: "; 
               cin >> response; 
             } 
             response = toupper(response); 
             uresponse[x] = response; 
             x++; 
           } 
         } 
//      cout << uresponse <<endl; 
//      system("pause"); 
       } 
        else 
    { 
      myfile.close(); 
    } 
     } 
     else 
       { 
       string line; 
       ifstream myfile ("form2.txt"); 
       getline (myfile,line); 
//    cout<< line<<endl; 
       for (int i = 0; i <= 19; i++) 
       { 
         answers[i] = line[i*2]; 
//      cout<<answers[i]<<endl; 
       } 
       getline (myfile,line); 

        if (myfile.is_open()) 
        { 
         int x = 0; 
         while (myfile.good()) 
         { 
          char answers[20]; 
           string line; 
           getline (myfile,line); 
//        cout << line << endl; 
           if(line == "") 
           { 
             cout << "Enter answer:"; 
             cin >> response; 
             if(response == 'a', 'A' || response == 'b', 'B' || response == 'c', 'C' || response == 'd', 'D') 
             { 
               response = response; 
             } 
             else 
             { 
               cout << "ERROR:You must enter A, B, C, or D. Please re-enter:"; 
               cin >> response; 
             } 
             response = toupper(response); 
             uresponse[x] = response; 
             x++; 
           } 
         } 
//      cout<<uresponse<<endl; 
//     system("pause"); 
       } 
        else 
    { 
      myfile.close(); 
    } 
     } 

     for (int j=0; j<20; j++) 
     { 
       if (answers[j] == uresponse[j]) 
         score += 1; 
     } 

     if(score >15) 
     { 
       cout << "CONGRATULATIONS! You Passed with a score of "; 
       cout << score << endl; 
       system("pause"); 
     } 
     else 
     { 
       cout<< "You Failed with a score of "; 
       cout << score << endl; 
       system("pause"); 
     } 
     system("pause"); 
     return 0; 
     }`enter code here` 

Answer 1

這可能是罪魁禍首：

answers[i] = line[i*2]; 

你一定i*2不是> = line.size()？

順便說一句，這個代碼看起來狡猾：

if(response == 'a', 'A' || response == 'b', 'B' 
|| response == 'c', 'C' || response == 'd', 'D') 
{ 
    response = response 
} 

也許你想使用switch和初始化響應本身..爲什麼？

編輯： 和你while(myfile.good()) 這可能執行100次，且不斷增加x 很難在你的代碼說..你有很多的「狡猾」行：P