常量数据成员作为类成员的对象

Question

所以我想写一个名为undergraduate的类，它将Phone类的对象作为参数。但是，电话类使用一个名为msg的常量数据成员。由于电话类中的const数据成员，这将不会编译。我如何解决它？任何帮助将不胜感激！

//下面是电话类的我的默认构造函数，它使用const的数据成员味精

Phone::Phone():msg(10){ //intialize const data member 

    areacode = 999; 

    exchange = 999; 

    line = 9999; 
} 

//这里是我的构造函数对象作为参数

Undergraduate::Undergraduate(Name sname, Date bday, Program sprogram, Phone sphone, char g, string s, int c, double G, int gdyr, string term){ 

    name = sname; 
    date = bday; 
    pgm = sprogram; 
    phone = sphone; 

    gender = g; 
    status = s; 
    credit = c; 
    gpa = G; 
    gradyear = gdyr; 
    gradterm = term; 
} 

Answer 1

我觉得这里的问题可能是你说的电话= sphone;这将需要改变const成员。您可以使用Undergraduate课程中的初始化程序列表来初始化它。

Undergraduate::Undergraduate(Name sname, Date bday, Program sprogram, Phone sphone, char g, string s, int c, double G, int gdyr, string term) 
: phone(sphone) 
{ 

    name = sname; 
    date = bday; 
    pgm = sprogram; 

    gender = g; 
    status = s; 
    credit = c; 
    gpa = G; 
    gradyear = gdyr; 
    gradterm = term; 
}