-- 作者:admin
-- 发布时间:11/9/2004 2:25:00 AM
-- C#快餐-1
发信人: walts (休息一会), 信区: DotNET 标 题: C#快餐-1 发信站: BBS 水木清华站 (Thu Jul 26 01:00:50 2001) Lesson 1. Hello World The simplest C# program is, of course, HelloWorld. You will need C# compiler, which comes as a part of .Net Framework Beta2 SDK. In your favorite text editor enter the following code: class hello //This program does not do much { static public void Main() { System.Console.WriteLine("Hello World"); } } Save this file as myhello.cs and type csc myhello.cs If you haven't made any typos, something like: Microsoft (R) Visual C# Compiler Version 7.00.9030 [CLR version 1.00.2204.21] Copyright (C) Microsoft Corp 2000. All rights reserved. will appear in your command prompt window. The C# compiler have created an executable code as a binary file in the PE format named myhello.exe. By simply typing myhello you will see Hello World What does this simple C# program look like? Java! Note that all methods end with semicolons and Main() method is a part of class Hello. Statements are enclosed in braces. Like in Java and C/C++, every program has a Main() entry point. However in Java the name of the program should be the same as the name of the class. There is no such restriction in C#. System.Console is a namespace that takes care of console I/O (see exercise 5). Other methods of System.Console include Write method which does not add carriage return at the end of the line and ReadLine which gets user input from the console. Exercises 1. Write a routine that asks a user some questions and gives meaningful output based on her answers. 2. Use your VC++ 6.0 compiler (not VC++ 7.0 that comes with Beta SDK) to compile the following program: #include<iostream> //This program does not do much { void main() { cout<<"Hello World"; } } Now, type dumbin /all myhello.exe >myhello.txt and dumbin /all myhelloC.exe to dump contents of myhello.exe and myhelloC.exe. Are executables myhello. exe and myhelloC.exe in the same binary format? Do you think myhelloC.exe would run on a computer which does not have .Net Framework installed.? 3. Rewrite the HelloWorld program in VB.Net 4. Rewrite the HelloWorld program in Managed C++ 5. I have mentioned that System.Console class takes care of Console I/O and error streams. Explore other classes in System namespace. 6. Find a mistake in this page. 7. Write a really cool program and send it to me. Do not forget to put a lot of comments. -- A great poem is a fountain forever overflowing with the waters of wisdom and delight. —— Shelley ※ 来源:·BBS 水木清华站 smth.org·[FROM: 166.111.142.118] 上一篇 返回上一页 回到目录 回到页首 下一篇
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