1 using System;
2 namespace HelloWorldApplication
3 {
4 class HelloWorld
5 {
6 static void Main(string[] args)
7 {
8 // 1
9 Console.WriteLine("Hello C# World!");
10 Console.WriteLine("A:{0}, B:{1}", 10, 20);
11 Console.WriteLine("A:{1}, B:{0}", 10, 20);
12 Console.WriteLine("A:{0}, B:", 10, 20);
13 Console.WriteLine("A:{1}, B:", 10, 20);
14 Console.WriteLine("A:, B:", 10, 20);
15 // 2
16 String str1 = "C:\\User";
17 String str2 = @"C:\User";
18 String str = @"
19 Hello C# World!
20 C# ------ very strong language.
21 ";
22 Console.WriteLine(str1);
23 Console.WriteLine(str2);
24 Console.WriteLine("{1}{0}{1}", str,"/");
25 //3
26 int val = 123;
27 Object box = val;
28 int valx = (int)box;
29 Console.WriteLine(box);
30 Console.WriteLine(val);
31 Console.WriteLine(valx);
32 //4
33 int a = 9;
34 Object obj;
35 obj = a;
36 obj = 10;
37 Console.WriteLine("a: {0}", a);
38 Console.WriteLine("obj: {0}", obj);
39 //string
40 string xStr = "Hello C#";
41 Console.WriteLine(xStr);
42 Console.ReadKey();
43 }
44 }
45 }
