轉 換 字 元

以何種形式列印對應的引數

c

字元

d or i

１０進位整數

o

無正負號８進位整數

x

無正負號１６進位整數

f

浮點數，例如 :7.123000

s

字串

變數宣告及設定初值  

char          c = 'w';  
int             i = 1, j = 29;
float         x = 333.12345678901234567890;
double        y = 333.12345678901234567890;
static char   s1[] = "she sells sea shells" ;
static char   s2[] = "by the seashore";

格式

運算式

列印在欄位上的結果

注 解

%c

c

"w"

預設的欄度長度為１

%2c

c

" w"

向右對齊

%-3c

c

"w  "

向左對齊

%d

 -j

"-29"

預設的欄度長度為３

%010d

i

"0000000001"

以０填補

%-12d

j

"29          "

向左對齊

%12o

j

"          35"

８進位 ,向右對齊

%-12x

j

"1d          "

１６進位 ,向左對齊

%f

x

"333.123456"

預設的精確度為６

%.1f

x

"333.1"

精確度為１

%20.3f

x

"             333.123"

向右對齊

%.9f

y

"333.123456789"

精確度為９

%s

s1

"she sells sea shells"

預設的欄度長度為２０

%7s

s1

"she sells sea shells"

需要更多的空間

%.5s

s2

"by th"

精確度為５

%-15.12s

s2

"by the seash   "

精確度為１２ ,向左對齊

/* printf example */
#include <stdio.h>
#include<stdlib.h>
int main()
{
   printf ("Characters: %c %c \n", 'a', 65);
   printf ("Decimals: %d %ld\n", 1977, 650000L);
   printf ("Preceding with blanks: %10d \n", 1977);
   printf ("Preceding with zeros: %010d \n", 1977);
   printf ("Some different radixes: %d %x %o %#x %#o \n", 100, 100, 100, 100, 100);
   printf ("floats: %4.2f %+.0e %E \n", 3.1416, 3.1416, 3.1416);
   printf ("Width trick: %*d \n", 5, 10);
   printf ("%s \n", "A string");
   system("PAUSE");
   return 0;
}