C#练习2

using System;
class Class1
{
public int vlaue = 0;
}
class Test
{
static void Main()
{
int v1 = 0;
int v2 = v1;
v2 = 123;
Class1 r1 = new Class1();
Class1 r2 = r1;
r2.vlaue = 123;
Console.WriteLine("Value:{0},{1}", v1, v2);
Console.WriteLine("Refs:{0},{1}", r1.vlaue, r2.vlaue);
}
}

using System;
public enum Color
{
    Red,Blue,Green
}
public struct Point
{
    public int x,y;
}
public interface IBase
{
    void F();
}
public interface IDerived:IBase
{
    void G();
}
public class A
{
    protected void H()
    {
        Console.WriteLine("A.H");
    }
}
public class B:A,IDerived
{
    public void F()
    {
        Console.WriteLine("B.F,implementation of IDerived.F");
    }
    public void G()
    {
        Console.WriteLine("B.G,implementation of IDerived.G");
    }
    override protected void H()
    {
        Console.WriteLine("B.H,override of A.H");
    }
}
//public delegate void EmptyDelegate();

using System;
class Test
{
    static void Main()
    {
        string s = "Test";
        string t = string.Copy(s);
        Console.WriteLine(s == t);
        Console.WriteLine((object)s == (object)t);
    }
}

using System;
class Test
{
    static void Main()
    {
        int intvalue = 123;
        long longvalue = intvalue;
        Console.WriteLine("(long){0}={1}", intvalue, longvalue);
    }
}

using System;
class Test
{
    static void Main()
    {
        long longValue = Int64.MaxValue;
        int intValue = (int)longValue;
        Console.WriteLine("(int){0}={1}", longValue, intValue);
    }
}

using System;
class Test
{
    static void Main()
    {
        int[] arr = new int[5];
        for (int i = 0; i < arr.Length; i++)
            arr[i] = i * i;
        for (int i = 0; i < arr.Length; i++)
            Console.WriteLine("arr[{0}]={1}", i, arr[i]);
    }
}

using System;
class Test
{
    static void Main()
    {
        int[] a1;
        int[,] a2;
        int[, ,] a3;
        int[][] j2;
        int[][][] j3;
    }
}

using System;
class Test
{
    static void Main()
    {
        int[] a1 = new int[] { 1, 2, 3 };
        int[,] a2 = new int[,] { { 1, 2, 3 }, { 4, 5, 6 } };
        int[, ,] a3 = new int[10, 20, 30];
        int[][] j2 = new int[3][];
        j2[0] = new int[] { 1, 2, 3 };
        j2[1] = new int[] { 1, 2, 3, 4, 5, 6 };
        j2[2] = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    }
}

using System;
class Test
{
    static void Main()
    {
        Console.WriteLine(3.ToString());
    }
}

using System;
class Test
{
    static void Main()
    {
        int i = 123;
        object o = i;
        int j = (int)o;
        Console.WriteLine(i);
        Console.WriteLine(o);
    }
}

using System;
class Test
{
    static void F(int p)
    {
        Console.WriteLine("p={0}", p);
        p++;
    }
    static void Main()
    {
        int a = 1;
        Console.WriteLine("pre:a={0}",a);
        F(a);
        Console.WriteLine("post:a={0}",a);
    }
}

using System;
class Test
{
  static void Swap(ref int a,ref int b)
    {
        int t = a;
        a = b;
        b = t;
    }
    static void Main()
  {
      int x = 1;
      int y = 2;
      Console.WriteLine("pre:x={0},y={1}", x, y);
      Swap(ref x, ref y);
      Console.WriteLine("post:x={0},y={1}", x, y);
  }
}