C++把一个字符放到一个cin的while循环会导致循环在其外执行

Question

我决定尝试做一个小游戏。这是一个简单的生存游戏。部分原因是人们试图通过选择选项尽可能长期生存。我已经尽可能地缩小了游戏的规模，从1000线到最小的情况。

在游戏的一部分，它问道：“你被一个礼物小丑拜访了，在0-10分的范围内，你想要礼物有多严重？

如果他们回答0-10，循环工作正常。如果他们回答一个角色，比如y或n，循环基本上会迫使游戏执行，不再要求玩家输入任何其他选择。

以前的while循环有效，只要玩家还活着，它就会继续。这个小丑while循环嵌套在它内部。我已经打破了与小丑部分的while循环，我认为这个问题是......并且还包括完整的代码，以防万一它不在里面。

我的目标很简单，如果一个角色被放入它，它不会打破这个游戏。

的main.cpp - 小丑节

encounterHurt = 0; 
randomEncounter = rand() % 8; 
cin.ignore(1, '\n'); 
if (randomEncounter == 1 && clown == true){ 
    encounterChoice = 1; 
    cout << "\n\nYou were visited by a gifting clown. \nOn a scale of 0-10, how badly do you want a gift? "; 
    while (encounterChoice >= 0 && encounterChoice <= 10){ 
     cin >> encounterChoice; 

     encounterFood = (rand() % 3) + encounterChoice/2; 
     encounterWood = (rand() % 3) + encounterChoice/2; 
     encounterMedicine = (rand() % 2); 
     encounterBullets = (rand() % 2); 

     if (encounterChoice > 0){ 
      encounterHurt = (rand() % 10) - encounterChoice; 

      if (encounterHurt <= 1){ 
    health--; 
    cout << "The crazy clown stabs you, but still provides gifts."; 
      } 
     } 
     if (encounterFood > 0) { 
      cout << "\nYou were provided with " << encounterFood << " food." << endl; 
      food += encounterFood; 
     } 
     if (encounterWood > 0) { 
      cout << "\nYou were provided with " << encounterWood << " wood." << endl; 
      wood += encounterWood; 
     } 
     if (encounterMedicine > 0) { 
      cout << "\nYou were provided with " << encounterMedicine << " medicine." << endl; 
      medicine += encounterMedicine; 
     } 
     if (encounterBullets > 0) { 
      cout << "\nYou were provided with " << encounterBullets << " bullets." << endl; 
      bullets += encounterBullets; 
     } 
    encounterChoice = 11; 
    } 

的main.cpp - 凝聚码

#include <iostream> 
#include <iomanip> 
#include <random> 
#include <stdlib.h> 
#include <time.h> 

using namespace std; 

int main() { 
    srand (time(NULL)); 
    int randNumber = 0; 
    int food = 4; 
    int wood = 4; 
    int medicine = 2; 
    int bullets = 8; 
    int money = 25; 
    int randomEncounter = 0; 
    int hunt = 0; 

    bool axe = false; 
    int axeTemp = 0; 
    int axeBonus = 0; 
    int lumberTemp = 0; 
    int lumber = 0; 

    int findStore = 0; 
    int storeChoice = 0; 

    bool gun = false; 
    int gunSearch; 
    int gunTemp; 
    int gunBonus = 0; 
    int gunFind = 0; 
// int searches; 
// int searchesBonus; 

    int farmFind = 0; 
    int farmFood = 0; 
    int farmSearch = 0; 
    bool farm = false; 
    string description; 

    int foodTemp = 0; 
    int woodTemp = 0; 
    int medicineTemp = 0; 
    int bulletsTemp = 0; 
    int moneyTemp = 0; 
    int huntTemp = 0; 
    int huntSuccess = 0; 
    char huntChoice; 

    int encounterFood = 0; 
    int encounterWood = 0; 
    int encounterBullets = 0; 
    int encounterMedicine = 0; 
    int encounterHurt = 0; 
    unsigned int encounterChoice = 0; 

    int hurt = 0; 
    int health = 3; 
    int healthMax = 3; 
    int days = 1; 

    char action = '0'; 
    char pause = '1'; 
    char classChoice; 
    char mainChoice; 

    bool clown = true; 
    int clownHealth = 5; 
    char clownChoice; 
    int yourShot = 0; 
    int clownShot = 0; 

    string place; 
    //Food 1 per day per person. Can expand to include more people. 
    //Fuel 1 per day, takes that much to stay warm even if fewer people 
    //Medicine used one per wound 
    //Bullets 1 to hunt, though can spend more to increase chance of success. 
    //Days how many days that they have survied. 
    //Health, everyone starts with three health. Good, okay, bad, dead. 
    cout << "\nFood: " << food << " Wood: " << wood << " Medicine: " << medicine << " Bullets: " << bullets << " Health: " << health << endl; 

    while (health > 0){ 
     cout << "\nDay: " << days; 
     cout << "\nFood: " << food 
      << "\nWood: " << wood 
      << "\nMedicine: " << medicine 
      << "\nBullets: " << bullets 
      << "\nHealth: " << health 
      << "\nMoney: " << money << endl; 

     if (food >= 1){ 
      food--; 
     } 

     if (wood >= 1){ 
      wood--; 
     } 

     if (food <= 0){ 
      health--; 
      cout << "Health lost due to lack of food" << endl; 
     } 

     if (health < healthMax && medicine > 0){ 
      health++; 
      medicine--; 
      cout << "Health pack used to heal your character\nHealth : " << health << endl; 
     } 


     action = '0'; 
     cout << "\n1: Find food" << endl; 

     cout << "What's your action? "; 
     cin >> action; 
     cout << endl; 

     if (action == '1'){ 
      // 
      //Section for random sites to search. 
      // 
      // 
     randNumber = rand() % 4; 
     description = ""; 
    //Maybe + days at the end, and subtract some, so that they eventually run out of places to check. 

     if (randNumber >= 0 && randNumber < 2) { 
      place = "supermarket"; 
      foodTemp = (rand() % 4) + 1; 
      woodTemp = (rand() % 2) + 0; 
      bulletsTemp = (rand() % 2) + 0; 
      medicineTemp = (rand() % 2) + 1; 
      moneyTemp = (rand() % 5) + 5; 
      } 

     if (randNumber >= 2 && randNumber < 4) { 
      place = "boat house"; 
      foodTemp = (rand() % 2) + 1; 
      woodTemp = (rand() % 4) + 1; 
      bulletsTemp = (rand() % 2) + 0; 
      medicineTemp = (rand() % 2) + 0; 
      moneyTemp = (rand() % 3) + 0; 
      } 

    cout << "You have come to the " << place << "." << endl; 
    cout << description << endl; 
    food += foodTemp; 
    wood += woodTemp; 
    bullets += bulletsTemp; 
    medicine += medicineTemp; 
    money += moneyTemp; 

    if (foodTemp > 0) 
     cout << "You have found " << foodTemp << " food." << endl; 
    if (woodTemp > 0) 
     cout << "You have found " << woodTemp << " wood." << endl; 
    if (medicineTemp > 0) 
     cout << "You have found " << medicineTemp << " medicine." << endl; 
    if (bulletsTemp > 0) 
     cout << "You have found " << bulletsTemp << " bullets." << endl; 
    if (moneyTemp > 0) 
     cout << "You have found " << moneyTemp << " money." << endl; 

    cout << "\nFood: " << food << " Wood: " << wood << " Medicine: " << medicine << " Bullets: " << bullets 
     << " Health: " << health << " Money: " << money << endl; 

      //End of search rooms. 
     } 

//Random encounter chance to see if they can gain additional items. 
     encounterHurt = 0; 
     randomEncounter = rand() % 8; 
     cin.ignore(1, '\n'); 
     if (randomEncounter == 1 && clown == true){ 
      encounterChoice = 1; 
      cout << "\n\nYou were visited by a gifting clown. \nOn a scale of 0-10, how badly do you want a gift? "; 
      while (encounterChoice >= 0 && encounterChoice <= 10){ 
    cin >> encounterChoice; 

    encounterFood = (rand() % 3) + encounterChoice/2; 
    encounterWood = (rand() % 3) + encounterChoice/2; 
    encounterMedicine = (rand() % 2); 
    encounterBullets = (rand() % 2); 

    if (encounterChoice > 0){ 
     encounterHurt = (rand() % 10) - encounterChoice; 

     if (encounterHurt <= 1){ 
      health--; 
      cout << "The crazy clown stabs you, but still provides gifts."; 
     } 
    } 
    if (encounterFood > 0) { 
     cout << "\nYou were provided with " << encounterFood << " food." << endl; 
     food += encounterFood; 
    } 
    if (encounterWood > 0) { 
     cout << "\nYou were provided with " << encounterWood << " wood." << endl; 
     wood += encounterWood; 
    } 
    if (encounterMedicine > 0) { 
     cout << "\nYou were provided with " << encounterMedicine << " medicine." << endl; 
     medicine += encounterMedicine; 
    } 
    if (encounterBullets > 0) { 
     cout << "\nYou were provided with " << encounterBullets << " bullets." << endl; 
     bullets += encounterBullets; 
    } 
      encounterChoice = 11; 
      } 


//Option to attack clown 
// 
// 
    } 
     //End of random encounter from the clown. 


//Pause mechanic to prevent the game from cycling. 
//   pause = 'b'; 
//   while (pause != 'a'){ 
//    cout << "\nEnter a to continue: "; 
//    cin >> pause; 
//   } 

//End of game message 
      cout << endl; 
      if (days == 100){ 
    cout << "You have made it to 100 days. You have beaten this game. You can quit now, or try to see how long you'll last." << endl; 
      } 

//Add day at end of while loop. 
      days++; 
     } 
    cout << "You have died after " << days << " days" << endl; 
} 

Answer 1

从another Stack Overflow问题...

当从读取时发生错误流，错误标志将被设置为 ，直到清除错误标志，才可能再次读取数据。 这就是为什么你得到一个无限循环。

cin.clear(); // clears the error flags 
// this line discards all the input waiting in the stream 
cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');