Question: constructor in constructor question (heap vs stack)

[toomanystars]

Hi guys,

I have a questions that's been bothering me for some time. Here's the scenario...

class Record{
public:
 Record():number(0){}
 Record(int num):number(num){}

 void init(int num){number=num;}
 int number;
};

class Student{
public:
 Student(){
   ptr_rec=new Record(10);//allowed
   rec.init(10);//allowed
   Record rec(10);//allowed but a difference object, therefore no good
   rec(10);//not allowed
 }
 ~Student(){
	delete ptr_rec;
 }
 void viewStudent(){
	std::cout<<rec.number<<std::endl;
 }
private:
 Record rec;
 Record *ptr_rec;
 
};

My question is: without going to the heap, or using an init() function, is it possible to initialize a constructor with arguments, in another constructor? And if not why not.

Thanks,

Mike

[Zhuge]

Yes; use the initializer list. In your case:

class Student {
public:
    Student() : rec(10) {
    }
    // ... 

http://www.cplusplus.com/doc/tutorial/classes/#member_initialization

[Cubbi]

Members are initialized before the opening brace, so

Student() : rec(10),
            ptr_rec(new Record(10))
{
}

[toomanystars]

Thanks guys, that anwsered my question