C ++ Constructor

1. Some members must be initialized in the constructor initialization list, and the constructor weight does not work for them. For example, a class member without the default constructor and a member of the const or reference type.

 # Pragma Once Class  Constref {  Public  : Constref (  Int  X );  //  ~ Constref (void );  Private  :  Const   Int  I;  Int IA;  Int & IB ;}; constref: constref (  Int  X): I (x), IB (x ){  //  I = X;  //  Error IA = X;  //  IB = x;/Error }

2. the initialization sequence of the members in the constructor is the same as that of the member declaration.