c++类的组合初始化

qq_36248786 2018-09-21 11:20:03

定义一个类的组合之后，怎么定义带有默认形参值的成员函数？（比如Line类的数据成员由Point类构成，现在定义一个Line类带有默认形参值的成员函数，该怎么定义）

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真相重于对错 2018-09-23

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Date(int y=0,int m=0,int d=0):year(y),month(m),day(d){}

引用 4 楼 qq_36248786 的回复:

class Date{
private:
int year,month,day;
public:
Date(int y,int m,int d):year(y),month(m),day(d){}
Date(){}
~Date(){}
void setDate(int y=00,int m=00,int d=00);
void show(){
cout<<year<<"."<<month<<"."<<day<<" . "<<endl;
}
};

enum GENDER{MALE=1,FEMALE};
class Person{
private:
int number;
GENDER sex;
Date birthdate;
unsigned int ID;
public:
Person(int n,GENDER s,Date b,unsigned int i):number(n),sex(s),birthdate(b),ID(i){}
Person(Person &p);
~Person(){}
void setPerson(int n=1,GENDER s=MALE,Date b={0,0,0},int i=000000000000000000);
void show(){
cout<<"The number "<<number<<" is a ";
switch (sex){
case 1:cout<<"Male.";break;
case 2:cout<<"Female.";break;
}
// switch (sex){
// case MALE:cout<<"Male.";break;
// case FEMALE:cout<<"Female.";break;
// }
cout<<endl;
cout<<"His/Her birthdate is ";
birthdate.show();
cout<<"And his/her ID is "<<ID<<" . "<<endl;
}
};
就这么一个例子，现在我想定义一个红色部分显示的成员函数，但里面的Date类不知道怎么给定默认形参值

qq_36248786 2018-09-23

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问题解决了谢谢大神们指教

qq_36248786 2018-09-22

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class Date{ private: int year,month,day; public: Date(int y,int m,int d):year(y),month(m),day(d){} Date(){} ~Date(){} void setDate(int y=00,int m=00,int d=00); void show(){ cout<<year<<"."<<month<<"."<<day<<" . "<<endl; } }; enum GENDER{MALE=1,FEMALE}; class Person{ private: int number; GENDER sex; Date birthdate; unsigned int ID; public: Person(int n,GENDER s,Date b,unsigned int i):number(n),sex(s),birthdate(b),ID(i){} Person(Person &p); ~Person(){} void setPerson(int n=1,GENDER s=MALE,Date b={0,0,0},int i=000000000000000000); void show(){ cout<<"The number "<<number<<" is a "; switch (sex){ case 1:cout<<"Male.";break; case 2:cout<<"Female.";break; } // switch (sex){ // case MALE:cout<<"Male.";break; // case FEMALE:cout<<"Female.";break; // } cout<<endl; cout<<"His/Her birthdate is "; birthdate.show(); cout<<"And his/her ID is "<<ID<<" . "<<endl; } }; 就这么一个例子，现在我想定义一个红色部分显示的成员函数，但里面的Date类不知道怎么给定默认形参值