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vc

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回复者：米罗 回复日期：2003-12-30 12:33:17
<br>内容：那你去看看c语言的printf函数吧。
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回复者：林建华 回复日期：2003-12-30 13:02:49
<br>内容：&lt;BLOCKQUOTE&gt;引用“第4楼”所言<BR>&lt;Q&gt;谢谢楼上的两位，不过，我实在太笨，iwill提供的那个例子我都快看睡着了，也没有看明白怎么用？&lt;/Q&gt;&lt;/BLOCKQUOTE&gt;<BR>那千万记得要把它打印出来贴在床前,以后睡不着的时候看看<BR>
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回复者：badboy 回复日期：2003-12-31 10:09:37
<br>内容：&nbsp;&nbsp; 我看的脑袋都疼了，也没有看懂！下面这个例子我怎么没有看出和printf()函数有关啊！？？ <BR><BR><BR>Example<BR><BR>/* VA.C: The program below illustrates passing a variable<BR> * number of arguments using the following macros:<BR> *&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;va_start&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;va_arg&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;va_end<BR> *&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;va_list&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; va_dcl (UNIX only)<BR> */<BR><BR>#include &lt;stdio.h&gt;<BR>#define ANSI&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;/* Comment out for UNIX version&nbsp;&nbsp;&nbsp;&nbsp; */<BR>#ifdef ANSI&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /* ANSI compatible version&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*/<BR>#include &lt;stdarg.h&gt;<BR>int average( int first, ... );<BR>#else&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /* UNIX compatible version&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*/<BR>#include &lt;varargs.h&gt;<BR>int average( va_list );<BR>#endif<BR><BR>void main( void )<BR>{<BR>&nbsp;&nbsp; /* Call with 3 integers (-1 is used as terminator). */<BR>&nbsp;&nbsp; printf( &#34;Average is: %d\n&#34;, average( 2, 3, 4, -1 ) );<BR><BR>&nbsp;&nbsp; /* Call with 4 integers. */<BR>&nbsp;&nbsp; printf( &#34;Average is: %d\n&#34;, average( 5, 7, 9, 11, -1 ) );<BR><BR>&nbsp;&nbsp; /* Call with just -1 terminator. */<BR>&nbsp;&nbsp; printf( &#34;Average is: %d\n&#34;, average( -1 ) );<BR>}<BR><BR>/* Returns the average of a variable list of integers. */<BR>#ifdef ANSI&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /* ANSI compatible version&nbsp;&nbsp;&nbsp;&nbsp;*/<BR>int average( int first, ... )<BR>{<BR>&nbsp;&nbsp; int count = 0, sum = 0, i = first;<BR>&nbsp;&nbsp; va_list marker;<BR><BR>&nbsp;&nbsp; va_start( marker, first );&nbsp;&nbsp;&nbsp;&nbsp; /* Initialize variable arguments. */<BR>&nbsp;&nbsp; while( i != -1 )<BR>&nbsp;&nbsp; {<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;sum += i;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;count++;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;i = va_arg( marker, int);<BR>&nbsp;&nbsp; }<BR>&nbsp;&nbsp; va_end( marker );&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;/* Reset variable arguments.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*/<BR>&nbsp;&nbsp; return( sum ? (sum / count) : 0 );<BR>}<BR>#else&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /* UNIX compatible version must use old-style definition.&nbsp;&nbsp;*/<BR>int average( va_alist )<BR>va_dcl<BR>{<BR>&nbsp;&nbsp; int i, count, sum;<BR>&nbsp;&nbsp; va_list marker;<BR><BR>&nbsp;&nbsp; va_start( marker );&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;/* Initialize variable arguments. */<BR>&nbsp;&nbsp; for( sum = count = 0; (i = va_arg( marker, int)) != -1; count++ )<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;sum += i;<BR>&nbsp;&nbsp; va_end( marker );&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;/* Reset variable arguments.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*/<BR>&nbsp;&nbsp; return( sum ? (sum / count) : 0 );<BR>}<BR>#endif<BR><BR><BR>Output<BR><BR>Average is: 3<BR>Average is: 8<BR>Average is: 0<BR><BR>