c++ - 读取中间名可选的文件

Question

我正在尝试读取格式为

的文件

firstName middleName_(optional) lastName petName\n

中间名出现在一半的条目上，我不确定读取这些条目并将它们放入正确的变量名中的最佳方法。任何帮助将不胜感激。

Answer 1

你可以这样做:

std::string line, word;
while (std::getline(myFile, line)) {
    if (line.empty()) continue;        

    // read words from line:
    std::istringstream is(line);
    std::vector<std::string> words;
    words.reserve(4);
    for (int i = 0; is >> words && i < 4; i++)
        words.push_back(word);

    if (words.size() == 4)
        // middle name was present ...
    else
        // it was not ...
}