how to initialize more than one const variable in a constructor c++?

Question

the header:

#ifndef EMPLOYEE_H_
#define EMPLOYEE_H_
#include "Date.h"
#include "String.h"

class Employee {
private:
    String firstname;
    String lastName;
    const Date birth;
    const int id;
    const Date start;
    double salary;
    int status;
public:
    Employee();
Employee(char* firstname,char* lastname,Date birth,int id,Date start,double salary,int status);
virtual ~Employee();
};

the cpp:

#include "Employee.h"
#include "Date.h"
#include "String.h"


Employee::Employee() :id( 0 ) {
    salary=0;
    status=0;
}
Employee::Employee(char* firstname,char* lastname,Date birth,int Id,Date start,double   salary,int status){
}

Employee::~Employee() {

}
#endif /* EMPLOYEE_H_ */

how to initialize all the const variables in the constructor??

@juanchopanza: That is not a duplicate. The OP appears to know about the initialization list, but doesn't realize it is a list, and can be used to initialize multiple members. And the duplicate you've marked doesn't show that either. — Benjamin Lindley, May 24 '14 at 17:40
Checkout this tutorial on initalization lists. http://www.cprogramming.com/tutorial/initialization-lists-c++.html — R Sahu, May 24 '14 at 17:48
@BenjaminLindley I see no evidence in OP's post that they knew about the initialization list. — juanchopanza, May 24 '14 at 18:04
@BenjaminLindley Somehow I missed that. I was looking at the other constructor, where there is no use if the initialization list. — juanchopanza, May 24 '14 at 18:06

score 5 · Answer 1 · answered May 24 '14 at 17:48

The method of initialization you used for id is part of the constructor's initialization list. It's a list, because it can be used to initialize multiple values, comma seperated. You can, and should, even use it to initialize non-const members, if possible.

Employee::Employee()
    :birth(args),
     id( 0 ),
     start(args),
     salary(0.0),
     status(0)
{}

Notice that I've ordered the members in the same order they appear in the class body. This is not a requirement, but is good practice, because that's the order they will be initialized in anyway, regardless of what order you list them in. This becomes especially important if the initialization of one member relies on the value of another.

how to initialize more than one const variable in a constructor c++?

1 Answers1