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<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>Hyperlinked ECMA C# Language Specification</title><meta name="author" content="Jon Jagger" /><link rel="stylesheet" href="ecma334.css"></link></head><body><div align="right"><em><a href="http://www.jaggersoft.com">Jon Jagger</a></em></div><div align="right"><a href="mailto:jon@jaggersoft.com">jon@jaggersoft.com</a></div><form method="get" action="http://search.atomz.com/search/"><input size="30" name="sp-q"></input><input type="submit" value="Search C# Spec"></input><input type="hidden" name="sp-a" value="sp10024177"></input><input type="hidden" name="sp-f" value="ISO-8859-1"></input></form><a href="toc.htm">Table of Contents</a> <a href="1.htm">1</a> <a href="2.htm">2</a> <a href="3.htm">3</a> <a href="4.htm">4</a> <a href="5.htm">5</a> <a href="6.htm">6</a> <a href="7.htm">7</a> <a href="8.htm">8</a> <a href="9.htm">9</a> <a href="10.htm">10</a> <a href="11.htm">11</a> <a href="12.htm">12</a> <a href="13.htm">13</a> <a href="14.htm">14</a> <a href="15.htm">15</a> <a href="16.htm">16</a> <a href="17.htm">17</a> <a href="18.htm">18</a> <a href="19.htm">19</a> <a href="20.htm">20</a> <a href="21.htm">21</a> <a href="22.htm">22</a> <a href="23.htm">23</a> <a href="24.htm">24</a> <a href="25.htm">25</a> <a href="notes.htm">Notes</a> <a href="HyperlinkedCSharpECMA.zip">Download</a><span class="ruler"></span><span class="heading">ECMA-334 C# Language Specification</span><span class="navigate"><a href="8.htm"><img src="previous.gif" alt="previous" border="0" /></a><a href="8.2.htm"><img src="next.gif" alt="next" border="0" /></a></span><span class="clause-depth"><a href="7.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="9.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number-link"><a href="8.htm">8</a></span><span class="clause-title-previous"> Language Overview</span></span><span class="clause-depth"><a href="8.1.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="8.2.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number">8.1</span><span class="clause-title"> Getting started</span></span><span class="informative"><span class="paragraph">The canonical "hello, world" program can be written as follows: <pre class="code-example">
using System;
class Hello
{
static void Main() {
Console.WriteLine("hello, world");
}
}
</pre></span><span class="paragraph">The source code for a C# program is typically stored in one or more text files with a file extension of .cs, as in hello.cs. Using a command-line compiler, such a program can be compiled with a command line like <pre class="code-example">
csc hello.cs
</pre>which produces an application named hello.exe. The output produced by this application when it is run is: <pre class="code-example">
hello, world
</pre></span><span class="paragraph">Close examination of this program is illuminating: <ul><li> The using System; directive references a namespace called System that is provided by the Common Language Infrastructure (CLI) class library. This namespace contains the Console class referred to in the Main method. Namespaces provide a hierarchical means of organizing the elements of one or more programs. A <span class="non-terminal"><a href="16.3.htm#using-directive">using-directive</a></span> enables unqualified use of the types that are members of the namespace. The "hello, world" program uses Console.WriteLine as shorthand for System.Console.WriteLine. </li><li> The Main method is a member of the class Hello. It has the static modifier, and so it is a method on the class Hello rather than on instances of this class. </li><li> The entry point for an application-the method that is called to begin execution-is always a static method named Main. </li><li> The "hello, world" output is produced using a class library. This standard does not include a class library. Instead, it references the class library provided by CLI. </li></ul></span><span class="paragraph">For C and C++ developers, it is interesting to note a few things that do not appear in the "hello, world" program. <ul><li> The program does not use a global method for Main. Methods and variables are not supported at the global level; such elements are always contained within type declarations (e.g., class and struct declarations). </li><li> The program does not use either "::" or "->" operators. The "::" is not an operator at all, and the "->" operator is used in only a small fraction of programs (which involve unsafe code). The separator "." is used in compound names such as Console.WriteLine. </li><li> The program does not contain forward declarations. Forward declarations are never needed, as declaration order is not significant. </li><li> The program does not use #include to import program text. Dependencies among programs are handled symbolically rather than textually. This approach eliminates barriers between applications written using multiple languages. For example, the Console class need not be written in C#. </li></ul></span></span><span class="ruler"></span><table><tr><td><table align="left" bgcolor="navy"><tr bgcolor="navy"><td><font face="Arial,sans-serif" size="6" color="yellow"><strong>{ JSL }</strong></font></td></tr></table></td></tr><tr><td><font face="Arial,sans-serif" size="2" color="navy"><strong>Jagger Software Ltd</strong></font></td></tr><tr><td><font face="Arial,sans-serif" size="2" color="navy"><strong>Company # 4070126</strong></font></td></tr><tr><td><font face="Arial,sans-serif" size="2" color="navy"><strong>VAT # 762 5213 42</strong></font></td></tr></table><img src="valid-html401.png" align="left" height="31" width="88" alt="Valid HTML 4.01" /><img src="vcss.gif" align="left" height="31" width="88" alt="Valid CSS" /></body></html>⌨️ 快捷键说明
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