Question

我需要做一个猜测的基本游戏，并且不知道如何循环代码，以便用户在遇到错误时再次输入他的答案。这是我写的整个代码：

#include <iostream>
#include <stdlib.h>      //srand
#include <time.h>       // time
#include <vector>
#include <stdexcept>

void error(std::string s)
{
    throw std::runtime_error(s);
}

int main()
{
    int characters ,length ,guess_number = 0,letter_number = 0, total_guess = 0 , err_count = 0;

    char letters,guess;
    std::vector <char> v;
    std::vector <char> answer;
    std::cout << "Enter the amount of different characters: ";
    std::cin >> characters;
    std::cout << "Enter the pattern length ";
    std::cin >> length;

    if(length > 26)
    {
        error("Length can't be over 26");
    }

    srand (time(NULL));

    for(int i =0; i < length ; i++)
    {
        letters = rand()% (26-(26-characters))+65;  //ascii code for Upper case letters. we discard the 26-characters to only generate random numbers up until how many characters.
        letter_number++;
        v.push_back(letters);                          //random letters
    }
    for(int i = 0;i <v.size(); i++)
        std::cout << v[i];

    try
    {
        while(guess_number != letter_number)
        {
            std::cout << "Enter your guess: ";
            while(std::cin >> guess)
            {
                answer.push_back(guess);                       //user guess
                if (std::cin.peek() == '\n')
                break;
            }
             total_guess ++;

            if(v.size() != answer.size())
            {   
                error("Answer too short");
            }

            for(int i = 0; i < v.size(); i++)
            {
                if(v[i] == answer[i])
                {
                    guess_number++;

                }
            }

            if(guess_number != letter_number)
            {
                std::cout << "you have guessed " << guess_number << " characters correctly." << std::endl;
                guess_number = 0;
                answer = {};
            }

            else if(guess_number == letter_number)
            {
                std::cout << "You have guessed " << guess_number << " characters correctly" << std::endl;
                std::cout << "You guesses the pattern in " << total_guess << " guesses";
                break;
            }

        }
    }

    catch(std::runtime_error& error)
    {
        std::cerr << "error: "<< error.what() << std::endl;

       return 1;
    }

    return 0;
}

基本上我不知道如果用户输入比随机字母向量更短的答案，如何让程序再次询问用户。在这部分之后：

if(v.size() != answer.size())
   {   
       error("Answer too short");
   }

在我运行它并输入一些简短的程序后，程序会给出错误并结束而不是再次运行。

Answer 1

您的代码失败，因为一旦错误被触发，您就会捕获错误（在while循环之外，基本上终止它），然后甚至执行return 1（终止程序）。此外，由于错误可能会提前停止执行，因此您应始终在开始每个步骤后立即清除answer。所以你应该做三件事：

将try...catch包裹在while
从catch中删除return 1行，以便代码继续执行
将answer = {};移至try...catch

看起来应该是这样的：

while(guess_number != letter_number)
{
    try
    {
        answer = {};
        std::cout << "Enter your guess: ";
        while(std::cin >> guess)
        {
            answer.push_back(guess);                       //user guess
            if (std::cin.peek() == '\n')
            break;
        }
         total_guess ++;

        if(v.size() != answer.size())
        {   
            error("Answer too short");
        }

        for(int i = 0; i < v.size(); i++)
        {
            if(v[i] == answer[i])
            {
                guess_number++;

            }
        }

        if(guess_number != letter_number)
        {
            std::cout << "you have guessed " << guess_number << " characters correctly." << std::endl;
            guess_number = 0;
        }

        else if(guess_number == letter_number)
        {
            std::cout << "You have guessed " << guess_number << " characters correctly" << std::endl;
            std::cout << "You guesses the pattern in " << total_guess << " guesses";
            break;
        }

    }
    catch(std::runtime_error& error)
    {
        std::cerr << "error: "<< error.what() << std::endl;
    }
}

在这里：tio.run 注意：我将您的代码更改为始终＆＃34;生成＆＃34; AB作为模式

如果遇到错误，如何重复代码？

1 个答案: