C++继承问题

Question

我有一些关于继承的问题。我有一类Person，和一类Student：Person，Employee：Person。我越来越困惑的错误 - 我不明白为什么我要得到它们。我使用微小的粘贴来粘贴代码，因为我认为这会占用太多空间。如果我应该在其他地方发表问题，请告诉我。谢谢。

代码文件：

• 的main.cpp - http://tinypaste.com/0775bea3
• Person.h - http://tinypaste.com/657638ef
• Person.cpp - http://tinypaste.com/934ee106
• Student.h -
• Student.cpp - http://tinypaste.com/b6259aa4
• Employee.h - http://tinypaste.com/f8b53d36
• Employee.cpp - http://tinypaste.com/1d939927

下面是我收到的错误：

1>------ Build started: Project: PR4_Students, Configuration: Debug Win32 ------ 
1>Build started 2/18/2012 11:14:27 PM. 
1>InitializeBuildStatus: 
1> Touching "Debug\PR4_Students.unsuccessfulbuild". 
1>ClCompile: 
1> main.cpp 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\student.h(15): error C2969: syntax error : ';' : expected member function definition to end with '}' 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\student.h(16): error C2059: syntax error : 'inline function header' 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\student.h(16): error C2630: ';' found in what should be a comma-separated list 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\employee.h(15): error C2969: syntax error : ';' : expected member function definition to end with '}' 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\employee.h(16): error C2059: syntax error : 'inline function header' 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\employee.h(16): error C2630: ';' found in what should be a comma-separated list 
1> Student.cpp 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\student.h(15): error C2969: syntax error : ';' : expected member function definition to end with '}' 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\student.h(16): error C2059: syntax error : 'inline function header' 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\student.h(16): error C2630: ';' found in what should be a comma-separated list 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\student.cpp(8): error C2084: function 'Student::Student(void)' already has a body 
1>   \\cs1\cs_students\mlindahl15\cs273\pr4_students\student.h(15) : see previous definition of '{ctor}' 
1> Employee.cpp 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\employee.h(15): error C2969: syntax error : ';' : expected member function definition to end with '}' 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\employee.h(16): error C2059: syntax error : 'inline function header' 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\employee.h(16): error C2630: ';' found in what should be a comma-separated list 
1>\\cs1\cs_students\mlindahl15\cs273\pr4_students\employee.cpp(8): error C2084: function 'Employee::Employee(void)' already has a body 
1>   \\cs1\cs_students\mlindahl15\cs273\pr4_students\employee.h(15) : see previous definition of '{ctor}' 
1> Generating Code... 
1> 
1>Build FAILED. 
1> 
1>Time Elapsed 00:00:05.64 
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== 

Answer 1

我没有分析整个代码，但你似乎很困惑如何声明调用基类的构造函数;

class Student : public Person 
{ 
... 
    Student() : Person(); 
... 
}; 

基类的构造函数的调用应在实际执行仅构造来完成。既然你已经做到这一点与

Student::Student() : Person() { 

你可以改变的声明

class Student : public Person 
{ 
... 
    Student(); 
... 
}; 

和事情的结果会更好。

编辑：在下面的后续问题中添加答案;

线

Employee(string department, string jobTitle, int yearOfHire) 
    : Person(name, socialSecurityNumber, age, gender, address, phoneNumber) { 

确实出于同样的原因没有真正意义。如果您希望能够使用所有这些参数构建一个Employee，则需要将该构造函数声明为;

Employee(string department, string jobTitle, int yearOfHire, name, 
     socialSecurityNumber, age, gender, address, phoneNumber) { 

并执行它作为

Employee::Employee(string department, string jobTitle, int yearOfHire, name, 
     socialSecurityNumber, age, gender, address, phoneNumber) 
    : Person(name, socialSecurityNumber, age, gender, address, phoneNumber) { 

从而传递参数到基类的构造。

Answer 2

在Students.h的第15行：

Student() : Person(); 

这是无效的。要么你需要在那里完全定义构造函数，要么根本不需要。

所以：

Student() : Person() { some code; }; 

或：

Student(); 

，并在您实现文件的实际代码。