无法退出do-while循环？

Question

我不明白为什么用户在输入中输入-1时do-while循环没有终止。只需忽略内部while循环之后的所有内容。我知道问题出在while循环中的某个地方。我就是看不出来。

int main()
{
    srand(time(0));
    int input;
    std::string pass, company, timeS;
    do
    {
        std::cout << "Enter password length: ";
        std::cin >> input;
        while(input < 8 || input > 16)
        {
            if(!std::cin)
            {
                std::cin.clear();
                std::cin.ignore(100, '\n');
            }

            std::cout << "Password length must be between 8 and 16.\nEnter password length: ";
            std::cin >> input;
        }

        std::cout << "Enter company name: ";
        std::getline(std::cin, company);

        pass = passGen(input);
        time_t now = time(0);
        auto time = *std::localtime(&now);
        std::stringstream ss;
        ss << std::put_time(&time, "%Y %b %d %H:%M:%S %a");
        timeS = ss.str();
        std::cout << "You passoword: " << pass << std::endl;
        writeFile(pass, company, timeS);

    }while(input != -1);

    return 0;
}

提前感谢！

Answer 1

内部while循环永远不会终止，因为条件为对于-1将始终为真。

int main()
{
    srand(time(0));
    int input;
    std::string pass, company, timeS;
    do
    {
        std::cout << "Enter password length: ";
        std::cin >> input;
        while((input < 8 && input>=0)|| input > 16)
        {
            if(!std::cin)
            {
                std::cin.clear();
                std::cin.ignore(100, '\n');
            }

            std::cout << "Password length must be between 8 and 16.\nEnter password length: ";
            std::cin >> input;
        }

        if (input>0){
          std::cout << "Enter company name: ";
          std::getline(std::cin, company);

          pass = passGen(input);
          time_t now = time(0);
          auto time = *std::localtime(&now);
          std::stringstream ss;
          ss << std::put_time(&time, "%Y %b %d %H:%M:%S %a");
          timeS = ss.str();
          std::cout << "You passoword: " << pass << std::endl;
          writeFile(pass, company, timeS);
        }
    }while(input != -1);

    return 0;
}

Answer 2

在此循环中，等待8到16之间的数字：

while(input < 8 || input > 16)
{
    if(!std::cin)
    {
        std::cin.clear();
        std::cin.ignore(100, '\n');
    }

    std::cout << "Password length must be between 8 and 16.\nEnter password length: ";
    std::cin >> input;
}

猜猜，什么东西永远不会从那个循环中出来？对，-1 !！=)

Answer 3

希望这能回答你的问题：

int main()
{
    srand(time(0));
    int input;
    std::string pass, company, timeS;
    // do
    // {
      while(true){
        std::cout << "Enter password length: ";
        std::cin >> input;
        if(input == -1){
          break;
        }
        while(input < 8 || input > 16)
        {
            if(!std::cin)
            {
                std::cin.clear();
                std::cin.ignore(100, '\n');
            }
            std::cout<< "=====>>>" << std::endl;

            std::cout << "Password length must be between 8 and 16.\nEnter password length: ";
            std::cin >> input;
        }
        std::cout << "Enter company name: ";
        std::getline(std::cin, company);

        pass = passGen(input);
        time_t now = time(0);
        auto time = *std::localtime(&now);
        std::stringstream ss;
        ss << std::put_time(&time, "%Y %b %d %H:%M:%S %a");
        timeS = ss.str();
        std::cout << "You passoword: " << pass << std::endl;
        writeFile(pass, company, timeS);
      }
    // }while(input != -1);

  return 0;
}

只需使用

while(true){
        //getting length of password  
        if(input == -1){
          break;
        }
        //rest of the logic
   }