我必须创建一个银行系统程序，它添加，删除，查找，保存到文件等。为此，我需要使用与下面的私有数据成员匹配的Vector，并建议使用push_back（）函数添加新帐户。
我能想出从提示中获取数据到向量（没有编译错误）的唯一方法是为Account创建一个构造函数，它包含int accountID，int passcode，string firstname，string lastname，double balance。然后，此构造函数初始化帐户中的所有私有数据成员，使用set（）函数列出相同的名称。
问题是当我使用accounts_.size（）函数查看向量是否有变化时，它总是输出1.
如何让向量输入向量的每个附加值？
更不用说在尝试任何矢量函数时总是会出现编译错误......
如果没有写出实际的代码，你们都能指出我正确的方向吗？谢谢！
----编辑 - 在下面添加了main.cpp和一个发布编译错误的cout循环示例
我遇到的问题是无论我输入多少次数据，大小都保持不变..所以当它编译时，似乎并没有将数据输入到向量中。
另外，当我试图看到向量中的内容时，我会收到编译错误：
bankingsys.cpp(36): warning C4018: '<' : signed/unsigned mismatch
bankingsys.cpp(37): error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'Account' (or there is no acceptable conversion)
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(679): could be 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(726): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(764): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(811): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(937): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const signed char *)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(944): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,signed char)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(951): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const unsigned char *)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(958): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,unsigned char)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(968): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>,Account>(std::basic_ostream<_Elem,_Traits> &&,_Ty)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>,
1> _Ty=Account
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(1085): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const std::error_code &)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(186): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(std::basic_ostream<_Elem,_Traits> &(__cdecl *)(std::basic_ostream<_Elem,_Traits> &))'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(192): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(std::basic_ios<_Elem,_Traits> &(__cdecl *)(std::basic_ios<_Elem,_Traits> &))'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(199): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(std::ios_base &(__cdecl *)(std::ios_base &))'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(206): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(std::_Bool)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(226): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(short)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(260): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(unsigned short)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(280): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(int)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(305): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(unsigned int)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(325): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(long)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(345): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(unsigned long)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(366): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(__int64)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(386): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(unsigned __int64)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(407): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(float)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(427): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(double)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(447): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(long double)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(467): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(const void *)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(487): or 'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(std::basic_streambuf<_Elem,_Traits> *)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> while trying to match the argument list '(std::ostream, Account)'
1>
1>Build FAILED.
答案 0 :(得分：1)
问题在于您的案例陈述......
switch ( inputcode )
{
case 1:// Add Account
{
BankingSystem add;
add.accAdd();
}
break;
case 2:// Delete Account
{
BankingSystem del;
del.accDelete();
}
break;
case 3:// Account Inquiry
{
BankingSystem inquire;
inquire.accInquiry();
}
break;
case 4: // Save Accounts to File
{
BankingSystem save;
save.accSave();
}
break;
case 5: // Load Accounts from File
{
BankingSystem load;
load.accLoad();
}
break;
您正在每个案例陈述中创建和使用BankingSystem类的新实例，而不是使用您在main()函数开头创建的实例。这就是为什么你总是得到size()的1.你想要使用myBankingSystem指针而不是......
switch ( inputcode )
{
case 1:// Add Account
myBankingSystem->accAdd();
break;
case 2:// Delete Account
myBankingSystem->accDelete();
break;
case 3:// Account Inquiry
myBankingSystem->accInquiry();
break;
case 4: // Save Accounts to File
myBankingSystem->accSave();
break;
case 5: // Load Accounts from File
myBankingSystem->accLoad();
break;
答案 1 :(得分：1)
如果您的代码无法编译，我不知道如何在运行时遇到问题:) 根据您发布的内容，
行cout << accounts_[i];
不起作用，因为运算符＆lt;＆lt;不知道谁来处理账户类型。
当你写cout＆lt;＆lt;某些东西，编译器实际上称为ostream＆amp;运算符＆lt;（某事）。 'something'必须是基本类型（int，float等等），或者是你定义了ostream＆amp;的重载的类型。运营商LT;＆LT; 。
所以，如果没有太多细节，你可以在这里找到2个简单的解决方案： - 写一个免费的函数ostream＆amp;运营商LT;＆LT; （ostream＆amp; out，const Account＆amp; val）;它负责按字段输出帐户。
ostream& operator<< (ostream& out,const Account& val);
{
out << val.getID() << endl;
out << val.getPass() << endl;
out << val.getLast() << endl;
out << val.getFirst() << endl;
out << val.getBalance() << endl;
}
- 写一个方法std :: string Account :: toString（）将一个帐号序列化为一个字符串，然后调用
out << accounts_[i].toString();
这将解决您的编译错误，并允许您显示Account实例的内容。由于矢量计数始终为1，请参阅Will的答案。
HTH