person类与其子类在使用中的内存情况(含java的改写和c#的屏蔽)

JAVA 普通person类及调用代码：

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public class Person

{

    public String xm;

    public int nl;

    public void setme(String x,int y)

    {

        xm=x;

        nl=y;

    }

    public void showme()

    {

        System.out.println("我是"+xm+",今年"+nl+"岁");

    }

}

public static void main(String[] args)

    {

        // TODO Auto-generated method stub

        Person a,b;

        a=new Person();

        b=new Person();

        a.setme("张三",20);

        b.setme("李四",18);

        a.showme();

        b.showme();

    }

C# 普通person类及调用代码：

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class Person     {         public String xm;         public int nl;         public void setme(String x, int y)         {             xm = x;             nl = y;         }         public void showme()         {             Console.WriteLine("我是" + xm + ",今年" + nl + "岁");         }     }     class Program     {         static void Main(string[] args)         {             Person a, b;             a = new Person();             b = new Person();             a.setme("张三", 20);             b.setme("李四", 18);             a.showme();             b.showme();             Console.ReadKey();         }     }

　　对应内存示意图（不严谨，仅为说明问题，下同）

JAVA person类的子类person1及调用代码：

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public class Person1 extends Person

{

    public void showme()

    {

        System.out.println("我是中国人"+xm+",今年"+nl+"岁");

    }

}

 

public static void main(String[] args)

    {

        // TODO Auto-generated method stub

        Person1 a;

        Person b,c;

        a=new Person1();

        b=new Person();

        a.setme("张三",20);

        b.setme("李四",18);

        c=a;

        a.showme();

        b.showme();

        c.showme();

    }

对应内存示意图:

运行结果：

C# person类的子类person1及调用代码： 

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class Person1 : Person     {           new public void showme()//没有new会报一个警告错误，不影响运行结果。以后会讲到。         {             Console.WriteLine("我是中国人" + xm + ",今年" + nl + "岁");         }     }     class Program     {         static void Main(string[] args)         {             Person1 a;             Person b,c;             a = new Person1();             b = new Person();             a.setme("张三", 20);             b.setme("李四", 18);             c = a;             a.showme();             b.showme();             c.showme();             Console.ReadKey();         }     }

　　对应内存示意图：

运行结果：