第1个回答 2013-08-12
printf([字符串][，变量]）
字符串：如"aabb"，"aaa%defdk","dsf%feadi"
变量：a,b,d,3,5,6...
可以只有字符串无变量，但是只有变量没有字符串，那就好无意义了。
为什么？不知道你没有没看到在上面的三个字符串中后面两个字符串中都有一个%，重点就在这里
%d表示int类型的值，看下面的例子你就会明白：
a=1,b=2
printf("a=%d,b=%d",a,b)
结果为：a=1,b=2
其中第一个%d会用第一个变量的值来代替，第二个%d会用第二个变量的值来代替。如果还有，则以此类推就可以了。
关于%d是什么，你就可以去参考第二位朋友的回答了！本回答被网友采纳
第3个回答 2013-08-12
printf, wprintf
Print formatted output to the standard output stream.
int printf( const char *format [, argument]... );
int wprintf( const wchar_t *format [, argument]... );
Routine Required Header Compatibility
printf <stdio.h> ANSI, Win 95, Win NT
wprintf <stdio.h> or <wchar.h> ANSI, Win 95, Win NT
For additional compatibility information, see Compatibility in the Introduction.
Libraries
LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version
Return Value
Each of these functions returns the number of characters printed, or a negative value if an error occurs.
Parameters
format
Format control
argument
Optional arguments
Remarks
The printf function formats and prints a series of characters and values to the standard output stream, stdout. If arguments follow the format string, the format string must contain specifications that determine the output format for the arguments. printf and fprintf behave identically except that printf writes output to stdout rather than to a destination of type FILE.
wprintf is a wide-character version of printf; format is a wide-character string. wprintf and printf behave identically otherwise.
Generic-Text Routine Mappings
TCHAR.H Routine _UNICODE & _MBCS Not Defined _MBCS Defined _UNICODE Defined
_tprintf printf printf wprintf
The format argument consists of ordinary characters, escape sequences, and (if arguments follow format) format specifications. The ordinary characters and escape sequences are copied to stdout in order of their appearance. For example, the line
printf("Line one\n\t\tLine two\n");
produces the output
Line one
Line two
Format specifications always begin with a percent sign (%) and are read left to right. When printf encounters the first format specification (if any), it converts the value of the first argument after format and outputs it accordingly. The second format specification causes the second argument to be converted and output, and so on. If there are more arguments than there are format specifications, the extra arguments are ignored. The results are undefined if there are not enough arguments for all the format specifications.
Example
/* PRINTF.C: This program uses the printf and wprintf functions
* to produce formatted output.
*/
#include <stdio.h>
void main( void )
{
char ch = 'h', *string = "computer";
int count = -9234;
double fp = 251.7366;
wchar_t wch = L'w', *wstring = L"Unicode";
/* Display integers. */
printf( "Integer formats:\n"
"\tDecimal: %d Justified: %.6d Unsigned: %u\n",
count, count, count, count );
printf( "Decimal %d as:\n\tHex: %Xh C hex: 0x%x Octal: %o\n",
count, count, count, count );
/* Display in different radixes. */
printf( "Digits 10 equal:\n\tHex: %i Octal: %i Decimal: %i\n",
0x10, 010, 10 );
/* Display characters. */
printf("Characters in field (1):\n%10c%5hc%5C%5lc\n", ch, ch, wch, wch);
wprintf(L"Characters in field (2):\n%10C%5hc%5c%5lc\n", ch, ch, wch, wch);
/* Display strings. */
printf("Strings in field (1):\n%25s\n%25.4hs\n\t%S%25.3ls\n",
string, string, wstring, wstring);
wprintf(L"Strings in field (2):\n%25S\n%25.4hs\n\t%s%25.3ls\n",
string, string, wstring, wstring);
/* Display real numbers. */
printf( "Real numbers:\n\t%f %.2f %e %E\n", fp, fp, fp, fp );
/* Display pointer. */
printf( "\nAddress as:\t%p\n", &count);
/* Count characters printed. */
printf( "\nDisplay to here:\n" );
printf( "1234567890123456%n78901234567890\n", &count );
printf( "\tNumber displayed: %d\n\n", count );
}