将int附加到std :: string

Question

为什么此代码给出调试断言失败？   std::string query;   int ClientID = 666;   query = "select logged from login where id = ";   query.append((char *)ClientID);

Answer 1

您不能将int强制转换为char *以获取字符串。尝试这个：

std::ostringstream sstream;

sstream << "select logged from login where id = " << ClientID;

std::string query = sstream.str();