c++ - 我使用什么函数来在 cin 语句中存储单个字符，以便我可以单独处理每个字符？

Question

我正在开发一个程序，假设要求用户输入一个词，然后用 CIAO 翻译它。但是，当我的程序编译时，它只处理第一个字母到我的 switch 语句中的单词长度的次数。我使用什么功能？

#include<iostream>
using namespace std;

int main()                                                                  
{                                                                           
    //Identify Variables                                                    
    string word;                                                            
    int counter;                                                            
    char letters, word1, word3;                                             

    //Ask user to input a word to be translated into I.C.A.O                
    cout<<" Enter a word: ";                                                
    cin>>word;                                                              

    counter = word.length(); //Counts the number of characters the user inputed
    word1 = word[0]; //Converts a string to a char value                 

    //Use a while statement to repeat until there are zero letters to process
    while(counter != 0)                                                     
    {                                                                       
        //Use a switch statement to translate each letter into I.C.A.O      
        switch(word1)                                                       
        {                                                                   
            case 'a': case 'A': cout<<"Alpha\n"; break;                     
            case 'b': case 'B': cout<<"Bravo\n"; break;                     
            case 'c': case 'C': cout<<"Charlie\n"; break;                   
            case 'd': case 'D': cout<<"Delta\n"; break;                     
            case 'e': case 'E': cout<<"Echo\n"; break;                      
            case 'f': case 'F': cout<<"Foxtrot\n"; break;                   
            case 'g': case 'G': cout<<"Golf\n"; break;                      
            case 'h': case 'H': cout<<"Hotel\n"; break;                     
            case 'i': case 'I': cout<<"India\n"; break;                     
            case 'j': case 'J': cout<<"Juliet\n"; break;                    
            case 'k': case 'K': cout<<"Kilo\n"; break;                      
            case 'l': case 'L': cout<<"Lima\n"; break;                      
            case 'm': case 'M': cout<<"Mike\n"; break;                      
            case 'n': case 'N': cout<<"November\n"; break;                  
            case 'o': case 'O': cout<<"Oscar\n"; break;                     
            case 'p': case 'P': cout<<"Papa\n"; break;                      
            case 'q': case 'Q': cout<<"Quebec\n"; break;                    
            case 'r': case 'R': cout<<"Romeo\n"; break;                     
            case 's': case 'S': cout<<"Sierra\n"; break;                    
            case 't': case 'T': cout<<"Tango\n"; break;                     
            case 'u': case 'U': cout<<"Uniform\n"; break;                   
            case 'v': case 'V': cout<<"Victor\n"; break;                    
            case 'w': case 'W': cout<<"Whiskey\n"; break;                   
            case 'x': case 'X': cout<<"X-Ray\n"; break;                     
            case 'y': case 'Y': cout<<"Yankee\n"; break;                    
            case 'z': case 'Z': cout<<"Zulu\n"; break;                      
        }                                                                   

        counter--;                                                          
    }                                                                       

    return 0;                                                               
}

Answer 1

您永远不会在循环中修改 word1，因此 switch 语句将始终选择您在循环之前对其进行初始化的第一个字母。

正确的做法是像这样遍历单词中的字符:

for (char c : word)
{                                                                       
    switch (c) {
        //...
    }
}

如果您使用的编译器不支持 C++11 功能，例如基于范围的循环(上面使用的)，您可以使用 oldskool:

for (size_t i = 0; i < word.size(); i++) {
    switch(word[i]) ...
}

或者:

for (std::string::const_iterator it = word.cbegin(); it != word.cend(); it++) {
    switch(*it) ...
}