此代码是类继承和虚函数的简单练习。案例类“人”派生员工，受抚养人，工人和经理。代码应显示一个输入屏幕，用户可以在其中输入10个人的数据，这取决于用户选择输入数据的人的类型。然后，当用户输入满意的数据时，按下1,2,3,4或5以外的按键将把它们带到显示菜单，在那里他们可以选择他们想要看的信息。
问题：main（）中的第一个for循环工作正常，数据最多可以输入10次。但是，下一个循环（显示循环）显示菜单，然后立即退出而不读取用户的决定。我无法弄清楚为什么会这样。 IT甚至会在最后跳过我的小测试输入，它只是退出程序？
不应该显示菜单，然后等待用户输入，然后继续或结束循环？
的main.cpp
using namespace std;
#include "person.h"
#include <iostream>
using namespace std;
int main()
{
worker w;
employee e;
dependent d;
manager m;
person p;
int decision;
for (int i=0; i<10; i++)
{
cout << "To enter employee information, press 1." << endl;
cout << "To enter dependent information, press 2." << endl;
cout << "To enter manager information, press 3." << endl;
cout << "To enter worker information, press 4." << endl;
cout << "To edit information for a person who is none of the above, press 5." << endl;
cout << "To display entered information, press anything else." << endl;
cin >> decision;
if (decision==1) //employee
{
e.obtain();
}
else if (decision==2) //dependent
{
d.obtain();
}
else if (decision==3) //manager
{
m.obtain();
}
else if (decision==4) //worker
{
w.obtain();
}
else if (decision==5) //other person
{
p.obtain();
}
else
{
break;
}
};
for (int i=0; i<10; i++)
{
cout << "To display employee information, press 1." << endl;
cout << "To display dependent information, press 2." << endl;
cout << "To display manager information, press 3." << endl;
cout << "To display worker information, press 4." << endl;
cout << "To display information for a person who is none of the above, press 5." << endl;
cout << "To exit, press anything else" << endl;
cin >> decision;
if (decision==1) //employee
{
e.display();
}
else if (decision==2) //dependent
{
d.display();
}
else if (decision==3) //manager
{
m.display();
}
else if (decision==4) //worker
{
w.display();
}
else if (decision==5) //other person
{
p.display();
}
else
{
break;
}
}
int test;
cin >> test;
return 0;
}
person.h
#ifndef PERSON_H
#define PERSON_H
#include <iostream>
#include <string>
using namespace std;
struct date //Structures defining date display and SSN display
{ //e.g. 3/12/14, XXX-XX-XXXX
int day;
int month;
int year;
};
struct SSN
{
int dig123;
int dig45;
int dig6789;
};
class person //Base class
{
public:
person();
virtual ~person();
virtual void obtain ();
virtual void display();
protected:
string name;
char gender;
date dob; //Date of Birth
SSN ssn;
string address;
int phone;
};
class employee: public person //Employee derived class
{
public:
employee();
~employee ();
void obtain();
void display();
private:
date doh; //Date of Hire
int salary;
string location;
int workphone;
};
class dependent: public person //Dependent derived class
{
public:
dependent();
~dependent();
void obtain();
void display();
private:
string address;
SSN ssn2; //SSN of employee of dependent
};
class manager: public person //Manager derived class
{
public:
manager();
~manager();
void obtain();
void display();
private:
string title;
};
class worker: public person
{
public:
worker();
~worker();
void obtain();
void display();
private:
string project;
};
#endif // PERSON_H
person.cpp
#include "person.h"
person::person()
{
}
person::~person()
{
}
void person::obtain ()
{
cout<<"Please enter information about the individual:" << endl;
cout<< "Name:" << endl;
getline (cin, name);
getline (cin, name);
cout<< "Gender (m or f): "<< endl;
cin>> gender;
cout<< "Date of Birth: Day? " << endl;
cin>> dob.day;
cout<< "Date of Birth: Month? " << endl;
cin>> dob.month;
cout<< "Date of Birth: Year? " << endl;
cin>> dob.year;
cout<< "Address: "<< endl;
getline (cin, address);
getline (cin, address);
cout<< "Phone number: " << endl;
cin>> phone;
cout<< "First three digits of SSN: " << endl;
cin>> ssn.dig123;
cout<< "Next 2 digits of SSN: " << endl;
cin>> ssn.dig45;
cout<< "Final 4 digits of SSN: " << endl;
cin>> ssn.dig6789;
}
void person::display()
{
cout<< "Name: " << name << endl;
if (gender=='m')
{
cout<<"Gender: "<<gender<< endl;
}
else if (gender=='f')
{
cout<<"Gender: "<< gender<<endl;
}
else
{
cout<<"You did not enter male(m) or female(f) as a gender."<<endl;
}
cout << "Date of Birth: " << dob.month << "/" << dob.day <<"/" << dob.year << endl;
cout << "Address: " << address << endl;
cout << "Phone number: " << phone << endl;
cout << "SSN: " << ssn.dig123 << "-" << ssn.dig45 << "-" << ssn.dig6789 << endl;
}
employee::employee():person()
{
}
employee::~employee()
{
}
void employee::obtain()
{
person::obtain();
cout<< "Date of Hire: Day? " << endl;
cin>> doh.day;
cout<< "Date of Hire: Month? " << endl;
cin>> doh.month;
cout<< "Date of Hire: Year? " << endl;
cin>> doh.year;
cout<< "Salary: $" << endl;
cin >> salary;
cout<< "Location: "<< endl;
getline (cin, location);
getline (cin, location);
cout<< "Work phone number: " << endl;
cin>> workphone;
}
void employee::display()
{
person::display();
cout << "Date of Hire: " << doh.month << "/" << doh.day <<"/" << doh.year << endl;
cout << "Location: " << location << endl;
cout << "Work phone number: " << workphone << endl;
}
dependent::dependent(): person()
{
}
dependent::~dependent()
{
}
void dependent::obtain()
{
person::obtain();
cout << "SSN of employee of which this person is a dependent:" << endl;
cout<< "First three digits of SSN: " << endl;
cin>> ssn2.dig123;
cout<< "Next 2 digits of SSN: " << endl;
cin>> ssn2.dig45;
cout<< "Final 4 digits of SSN: " << endl;
cin>> ssn2.dig6789;
cout << "Address (if different from employee's address): " << endl;
cout<< "Address: "<< endl;
getline (cin, address);
getline (cin, address);
}
void dependent::display()
{
person::display();
cout<< "Address: " << address << endl;
cout << "SSN of employee: " << ssn2.dig123 << "-" << ssn2.dig45 << "-" << ssn2.dig6789 << endl;
}
worker::worker():person()
{
}
worker::~worker()
{
}
void worker::obtain()
{
person::obtain();
cout << "Project: " << endl;
getline (cin, project);
}
void worker::display()
{
person::display();
cout << "Project: " << project << endl;
}
manager::manager():person()
{
}
manager::~manager()
{
}
void manager::obtain()
{
person::obtain();
cout << "Title: " << endl;
getline (cin, title);
getline (cin, title);
}
void manager::display()
{
person::display();
cout << "Title: " << title << endl;
}
如果有人能帮我解释为什么会这样，我将非常感激。
答案 0 :(得分：4)
cin >> decision;只读取一个\ n或一个空格，一旦它从输入缓冲区中取出你的字符串，仍然会留下\ n。所以在第二次迭代时，当你再次到达cin >> decision;时，它会读到\ n并退出。您需要通过调用getline清除缓冲区以消耗左侧的\ n。
答案 1 :(得分：1)
1）在第一个for循环结束时不需要分号。
2）如果正在跳过输入，则很可能在正在读取的输入缓冲区中有垃圾。在第二个循环之前尝试这个：
std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');