Order of calling base class constructor from derived class initialization list

Question

struct B { 
  int b1, b2;  
  B(int, int);
};

struct D : B {
  int d1, d2;
// which is technically better ?
  D (int i, int j, int k, int l) : B(i,j), d1(k), d2(l)          


        

Answer 1

The order is well defined. It does not depend on how you specify them while initializtion.
Base class constructor B will be called first and then the member variables(d1 & d2) in the order in which they are declared.

To explain the comment in @Andrey T's answer.

class MyClass1: public MyClass2, public virtual MyClass3
{


};

The order of calling the Base class constructors is well defined by the standard and will be:

MyClass3  
MyClass2
MyClass1

The virtual Base class MyClass3 is given preference over Base Class MyClass2.