C++ 成员函数的无效使用(你忘记了 '()' 了吗？)

Question

我在编译我的程序时遇到了问题。错误发生在第 165-177 行。我添加的只是对字母存在的测试，我得到了一个错误，希望你能帮忙!完整代码 http://pastebin.com/embed.php?i=WHrSasYk

(下面附上代码)

do
{
  cout << "\nCustomer Details:";

  cout << "\n\tCustomer Name:";
  cout << "\n\t\tFirst Name:";
  getline (cin, Cust_FName, '\n');
  if (Quotation::Cust_FName.length() <= 1)
    ValidCustDetails = false;
  else
  {
    // Error line 165!
    for (unsigned short i = 0; i <= Cust_FName.length; i++)
      if (!isalpha(Quotation::Cust_FName.at(i)))
        ValidCustDetails = false;
  }
  cin.ignore();
  cout << "\t\tLast Name:";
  getline (cin, Cust_LName, '\n');
  if (Cust_LName.length () <= 1)
    ValidCustDetails = false;
  else
  {
    // Error line 177!
    for (unsigned short i = 0; i <= Cust_LName.length; i++)
      if (!isalpha(Cust_LName.at(i)))
        ValidCustDetails = false;
  }
  cin.ignore();
}
while(!ValidCustDetails);

Answer 1

这些行是你的问题:

for (unsigned short i = 0; i <= Cust_FName.length; i++)
for (unsigned short i = 0; i <= Cust_LName.length; i++)
//                                              ^^

std::string::length 是一个函数，所以你需要用括号调用它:

for (unsigned short i = 0; i <= Cust_FName.length(); i++)
for (unsigned short i = 0; i <= Cust_LName.length(); i++)