類指標

一個指向類是做完全相同的方式作為一個指向結構和存取指標的成員使用成員存取運算子類- >操作符，就像結構體指標。與其它的指標一樣，必須在使用前初始化指標。

讓我們試試下面的例子就明白了指標指向一個類的概念：

import std.stdio;

class Box
{
   public:
      // Constructor definition
      this(double l=2.0, double b=2.0, double h=2.0)
      {
         writeln("Constructor called.");
         length = l;
         breadth = b;
         height = h;
      }
      double Volume()
      {
         return length * breadth * height;
      }
   private:
      double length;     // Length of a box
      double breadth;    // Breadth of a box
      double height;     // Height of a box
}

void main()
{
   Box Box1 = new Box(3.3, 1.2, 1.5);    // Declare box1
   Box Box2 = new Box(8.5, 6.0, 2.0);    // Declare box2
   Box *ptrBox;                // Declare yiibaier to a class.

   // Save the address of first object
   ptrBox = &Box1;

   // Now try to access a member using member access operator
   writeln("Volume of Box1: ",ptrBox.Volume());

   // Save the address of first object
   ptrBox = &Box2;

   // Now try to access a member using member access operator
   writeln("Volume of Box2: ", ptrBox.Volume());
}

讓我們編譯和執行上面的程式，這將產生以下結果：

Constructor called.
Constructor called.
Volume of Box1: 5.94
Volume of Box2: 102