类例题：球继承圆类(不含屏蔽改写)

Java:

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class circle {     int r;     float S()     {         return 3.14f * r * r;     } } class ball extends circle {     float V()     {         return 4 / 3f * 3.14f * r * r * r;     } } public class c1 {     public static void main(String[] args)     {         // TODO Auto-generated method stub         ball b = new ball();         　　　　　b.r = 2;         　　　　  System.out.println("球的截面积是：" + b.S() + "球的体积是:" + b.V());     } }

　　

c#:

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class circle     {         public int r;         public float S()         {             return 3.14f * r * r;         }     }     class ball:circle     {         public float V()         {             return 4 / 3f * 3.14f * r * r * r;         }     }     class Program     {         static void Main(string[] args)         {             ball b = new ball();             b.r = 2;             Console.WriteLine("球的截面积是：" + b.S() + "球的体积是:" + b.V());             Console.ReadKey();         }     }

　　内存示意：