PRODUCT  :  Turbo C++                              NUMBER  :  805
  VERSION  :  All
       OS  :  DOS
     DATE  :  October 19, 1993                         PAGE  :  1/2

    TITLE  :  Member Data Initialization -- Using a Constructor
              Initialization List




  The following code demonstrates the initialization of a class's
  member data by using the initialization list of a class
  constructor.  It also shows how to call a base class constructor
  from a derived class.

  Since this code uses floating point, be sure to have floating
  point emulations enabled (IDE) or include EMU.LIB and MATHx.LIB
  at the appropriate location in the TLINK command line.

  #include <iostream.h>
  #define HUND 100

  class base {
    public:
      base() { cout << "in base\n"; }
  };

  class derive : public base {
      int x, z;
      float y;

    public:
      /* Note that the initialization list comes AFTER the
         contructors formal arguments and a colon. Each
         variable name is followed by an initial value in
         parentheses.  Each variable is separated from the
         next by a comma.  The value in the parentheses can
         be either a variable from the constructor parameter
         list, a value, an expression that results in a value,
         or a constant.

         At the end of the initialization list is the call to
         the base class constructor.  In this example, parameters
         are not passed, however, parameters may be passed and
         they may consist of a variable from the derived
         constructor parameter list, a value, an expression
         that results in a value, or a constant.

         Note: a private or public member of the base class
               cannot be initialized by the initialization list
               of the derived constructor.
      */













  PRODUCT  :  Turbo C++                              NUMBER  :  805
  VERSION  :  All
       OS  :  DOS
     DATE  :  October 19, 1993                         PAGE  :  2/2

    TITLE  :  Member Data Initialization -- Using a Constructor
              Initialization List




  // initialization list Call to base constructor
  derive(int a) : x(a*a), z(HUND), y(4.33), base()
  {
      cout << "in derive\n";
  }

  void show(void)
  {
      cout << "x is " << x;
      cout << "\nz is " << z;
      cout << "\ny is " << y;
  };

  main()
  {
      derive dd(3);
      dd.show();
  }
  DISCLAIMER: You have the right to use this technical information
  subject to the terms of the No-Nonsense License Statement that
  you received with the Borland product to which this information
  pertains.