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C++ クラスの最終プロジェクトに取り組んでいます。answer.txtこれは、ユーザーの回答と、 20 の回答すべてを含むにある対応する回答を比較することによって、正しい回答を確認する必要がある多肢選択式クイズです。また、学生の名前とスコアは、学生が自分のスコアを表示できるようにする別のテキスト ファイルにある必要があります。この授業で学んだことから、プログラムanswer.txtscores.txt PLUS 2 つの機能、およびその他のすべてを使用する必要があります。

ファイルから個々の回答を読み取ることができませんanswer.txt。一度に 1 つの回答を読み取って、ユーザーが という関数内ですべて入力した回答と比較しようとしていますcheck_answer。文字の代わりに整数を使用して、大文字と小文字を簡単にチェックできるようにしています (32 を追加することにより)。プログラムはコンパイルされますが、唯一の問題は、最初の質問に答えた後、他のすべての質問が表示され"You answered correctly!"、プログラムの実行が終了することです。

DevC++ を使用しています。以下は、私のプログラムのコードと txt ファイルの内容ですanswers.txt

#include<iostream.h>
#include<fstream.h>
#include<string.h>

int total_correct = 0;
ifstream infile;

void name_prompt();
void check_answer();
void scores();

int main()
{
      name_prompt();

      cout << "\nGREAT WHITE SHARK TRIVIA\n";
      cout << "Enter the letter corresponding to the correct answer choice, then press enter.\n";

      cout << "\nQuestion 1\n" << "What is the Great White Shark's scientific name?\n";
      cout << "A. Hemipristis elongatus" << endl;    // Snaggletooth shark
      cout << "B. Odontaspis ferox" << endl;         // Smalltooth sand tiger
      cout << "C. Carcharodon carcharias" << endl;   // Great White Shark
      cout << "D. Oxynotus caribbaeus" << endl;      // Caribbean roughshark
      check_answer();

      cout << "\nQuestion 2\n" << "Carcharodon is a mix of two Greek words that translate in English to:\n";
      cout << "A. Ragged tooth" << endl;    
      cout << "B. Swift killer" << endl;        
      cout << "C. White fish" << endl; 
      cout << "D. Sea warrior" << endl;     
      check_answer();

      cout << "\nQuestion 3\n" << "How big do Great White Sharks grow?\n";
      cout << "A. Approximately 10 feet long" << endl;    
      cout << "B. Approximately 17 feet long" << endl;        
      cout << "C. Approximately 21 feet long" << endl; 
      cout << "D. Approximately 30 feet long" << endl;  
      check_answer();

      cout << "\nQuestion 4\n" << "What is the name of the organ on the Great White Shark that allows it to\nsense electromagnetic fields radiating from its prey?\n";
      cout << "A. Duodenom antennae" << endl;    
      cout << "B. Ampullae of Lorenzini" << endl;        
      cout << "C. Spiracle gland" << endl; 
      cout << "D. Dermal denticles" << endl;     
      check_answer();

      cout << "\nQuestion 5\n" << "How long do Great White Shark mothers stay with their young?\n";
      cout << "A. No time whatsoever" << endl;    
      cout << "B. 3 months" << endl;        
      cout << "C. 6 months" << endl; 
      cout << "D. 1 year" << endl;     
      check_answer();

      cout << "\nQuestion 6\n" << "How old are female Great Whites when they usually bear their first young?\n";
      cout << "A. 2-4 years" << endl;    
      cout << "B. 6-8 years" << endl;        
      cout << "C. 8-10 years" << endl; 
      cout << "D. 12-14 years" << endl;     
      check_answer();

      cout << "\nQuestion 7\n" << "What is the favorite prey of an adult Great White Shark?\n";
      cout << "A. Crustaceans" << endl;    
      cout << "B. Fish" << endl;        
      cout << "C. Plankton" << endl; 
      cout << "D. Sea mammals" << endl;     
      check_answer();

      cout << "\nQuestion 8\n" << "What is the tactic used by Great Whites to attack prey on the surface\nof the water?\n";
      cout << "A. Attack from the side" << endl;    
      cout << "B. Attack from below" << endl;        
      cout << "C. Jump out of the water and land on the desired target" << endl; 
      cout << "D. Wait until the surface prey dives and then attack" << endl;     
      check_answer();

      cout << "\nQuestion 9\n" << "After spotting surface prey from below, Great Whites swim upward and launch\nthemselves out of the water grabbing their prey. This is called: \n";
      cout << "A. Skipping" << endl;    
      cout << "B. Jumping" << endl;        
      cout << "C. Breaching" << endl; 
      cout << "D. Charging" << endl;     
      check_answer();

      cout << "\nQuestion 10\n" << "How do Great White Sharks consume their food?\n";
      cout << "A. Rip off chunks of meat and swallow them whole" << endl;    
      cout << "B. Chew thoroughly and swallow" << endl;        
      cout << "C. Hold in mouth, let saliva break it down, and then swallow" << endl; 
      cout << "D. Suck out bodily fluids and leave carcass" << endl;     
      check_answer();

      cout << "\nQuestion 11\n" << "Of the following, which is the best location to view Great White\nbreaching behavior?\n";
      cout << "A. Myrtle Beach, South Carolina" << endl;    
      cout << "B. Cape Cod, Massachusetts" << endl;        
      cout << "C. Oban, Scotland" << endl; 
      cout << "D. False Bay, South Africa" << endl;     
      check_answer();

      cout << "\nQuestion 12\n" << "On average, how many non-fatal Great White Shark attacks occur each year?\n";
      cout << "A. 2-3" << endl;    
      cout << "B. 3-4" << endl;        
      cout << "C. 8-10" << endl; 
      cout << "D. 15-20" << endl;     
      check_answer();

      cout << "\nQuestion 13\n" << "What is one of the main predators juvenille Great Whites have to watch out for?\n";
      cout << "A. Humboldt Squid" << endl;    
      cout << "B. Various Whale Species" << endl;        
      cout << "C. Lion's Mane Jellyfish" << endl; 
      cout << "D. Other Great White Sharks" << endl;     
      check_answer();

      cout << "\nQuestion 14\n" << "After eating a marine mammal (such as a seal or sea lion), a Great White\nShark can go how long without another large meal?\n";
      cout << "A. 3-4 days" << endl;    
      cout << "B. 1 week" << endl;        
      cout << "C. 2 weeks" << endl; 
      cout << "D. 1-2 months" << endl;     
      check_answer();

      cout << "\nQuestion 15\n" << "How fast can adult Great White Sharks swim?\n";
      cout << "A. Up to 64 mph" << endl;    
      cout << "B. Up to 43 mph" << endl;        
      cout << "C. Up to 20 mph" << endl; 
      cout << "D. Up to 14 mph" << endl; 
      check_answer();

      cout << "\nQuestion 16\n" << "The teeth of a Great White Shark can measure up to?\n";
      cout << "A. 0.5 in" << endl;    
      cout << "B. 1.0 in" << endl;        
      cout << "C. 2 in" << endl; 
      cout << "D. 2.5 in" << endl;         
      check_answer();

      cout << "\nQuestion 17\n" << "Great White Sharks have which of the following?\n";
      cout << "A. Acute hearing" << endl;    
      cout << "B. Good eyesight" << endl;        
      cout << "C. Keen sense of smell" << endl; 
      cout << "D. All of the above" << endl;     
      check_answer();

      cout << "\nQuestion 18\n" << "In addition to its normal function, a Great White Shark's liver helps it to:\n";
      cout << "A. Float" << endl;    
      cout << "B. Swim aerodynamically" << endl;        
      cout << "C. Sense prey" << endl; 
      cout << "D. All of the above" << endl;     
      check_answer();

      cout << "\nQuestion 19\n" << "Great White Sharks can detect tiny amounts of blood up to how far away?\n";
      cout << "A. 500 feet" << endl;    
      cout << "B. 1 mile" << endl;        
      cout << "C. 3 miles" << endl; 
      cout << "D. 5 miles" << endl;     
      check_answer();

      cout << "\nQuestion 20\n" << "Great White Shark's mouths contain up to how many teeth?\n";
      cout << "A. 50" << endl;    
      cout << "B. 100" << endl;        
      cout << "C. 200" << endl; 
      cout << "D. 300" << endl;     
      check_answer();

      scores();

      system("pause");
      return 0;
}

void name_prompt()
{
     char user_name[30];
     ofstream outfile;

     cout << "Please enter your name: ";
     cin.get(user_name, 30);

     outfile.open("SCORES.TXT", ios::out);

     if(!outfile)
      {
                 cout << "Error opening file.\n";
      }

      outfile << user_name << endl;
      outfile.close();
}

**void check_answer()
{
      ifstream infile;
      infile.open("ANSWERS.TXT", ios::in);

      if(!infile)
      {
                 cout << "Error opening file.\n";
      }

     int x, answer;

      cin >> x;

      infile >> answer;

      if(x == answer || x == (answer + 32))
      {
           cout << "You answered correctly!\n" << endl;
           total_correct++;
      } 
      else
      {
          cout << "You answered incorrectly.\n" << endl;
      }
      infile.close();
}**

void scores()
{
     ofstream outfile2;         
     int score;

     score = (total_correct * 5);

     outfile2.open("SCORES.TXT", ios::app);

     if(!outfile2)
      {
                 cout << "Error opening file.\n";
      }

      outfile2 << "You answered " << total_correct << " out of 20 questions correctly." << endl;
      outfile2 << "You earned a score of " << score << "%.\n";
      outfile2.close();

      cout << "Please see SCORES.TXT if you wish to view your results." << endl;
}

「answers.txt」の内容:

C
A
C
B
A
D
D
B
C
A
D
A
D
D
B
D
D
A
C
D

助けていただければ幸いです。この度はご覧いただき誠にありがとうございました!

4

1 に答える 1

1

問題は、文字を整数に読み込もうとしていることだと思います:

int x, answer;

cin >> x;

基本的には「標準入力から整数cin >> xを読み込む」と言います。問題は、ストリームに整数がなく、文字だけであることです。したがって、読み取り操作は失敗しその文字はストリームに残ります。次に答えを読もうとすると、同じ文字を何度も読むことになります。x

まず、整数を使用して答えを読み取るという選択を再考する必要があります。達成したい目的のために本当に整数が必要ですか? 算術演算も使用できますchar...

そして、一般的なアドバイス: 常にデータをコードから分離してください... この場合、質問を別のファイルに入れる必要があります。これにより、コードが読みやすくなり、管理しやすくなります。

于 2012-05-19T23:18:13.210 に答える