C++ 省略或添加额外字符

Question

所以我有一个有趣的错误。我有这段代码(这是部分代码):

 if (isQuote(ch))
                {
                    //Add it to the Buffer
                    strBuffer += ch;

                    do
                    {
                        //get Next Character from ifstream and add it to the strBuffer
                        getNextAndAdd(ch);


                        // check whether it is a \\'
                        if (isBackslash(ch) && (this -> peek() == '"'))
                        {
                            //if it is a backslash, activate check checkQuote
                            checkQuote = true;
                        }
                        //if it is another quote, dectivate check Quote otherwise, break the system
                        if (isQuote(ch))
                        {
                             if (checkQuote)
                             {
                                 checkQuote = false;
                             }
                             else
                             {
                                 break;
                             }
                        }
                        //IF EOF, do NOT continue repeating the last character
                        if (input -> eof()){break;}

                    }
                    while (isPrintable(ch)); // check that it falls within the SXL acceptance range
                    if (ch == '"')
                    {
                        //IF EOF, do NOT continue repeating the last character
                        if (input -> eof()){break;}

                        //output Buffer for TEST purposes
                        cout << strBuffer << endl;

                        //create new token and push it into the vector
                        tk = new Token (tkstring, strBuffer, row, col);
                        tokensUsed.push_back(tk);
                        startNewString();
                    }
                    tokenMatch = true;
                }

getNextAndAdd(ch) 转换为

void getNextAndAdd(char ch)
    {
       ch = nextChar();
       strBuffer += ch;
    }

我正在给它一些测试数据。我有一个文本文件，我在其中输入了测试数据。问题在于，如果我写例如 "abc""def"，它们之间只有一个空格，它将读作 "abc"123，后者是一个数字，完全不同，如果我做两个空格，意思是 "abc""def"然后它会将其读取为 2 个字符串。我还检查了它是否是一个空白，但是后一种有 2 个空格的情况已经识别出最后一个空白实际上是一个空白

知道为什么吗？我尝试删除字符串的最后一个字母说可能是那个错误但它以 "hello

结尾

谢谢

Answer 1

void getNextAndAdd(char ch)
{
   ch = nextChar();
   strBuffer += ch;
}

您可能认为这会返回您刚刚在 ch 中读取的字符。你会错的。

结果，执行这段代码后:

if (isQuote(ch))
{
    //Add it to the Buffer
    strBuffer += ch;

    do
    {
        //get Next Character from ifstream and add it to the strBuffer
        getNextAndAdd(ch);

ch 将包含一个引号，并且两个引号将附加到 strBuffer。