4-3.txt

C++完美演绎 经典算法 如 /* 头文件：my_Include.h */ #include <stdio.h> /* 展开C语言的内建函数指令 */ #define PI 3.141

/* 范例：4-3 */
#include <stdio.h>
void main()
{
  int a = 123;
  double ff = 0.01234567890;
  char *str = "123456";

  /* int(%d,%i,%o,%u,%x) */
  /* only width */
  printf("int(d,i,o,u,x)........(ex: a=123)\n");
  printf("#%2d#%3d#%4d#(%%2d,%%3d,%%4d)\n",a,a,a);/* #1 */
  printf("#%02d#%03d#%04d#(%%02d,%%03d,%%04d)\n",a,a,a);
                                                        /* #2 */
  printf("#%*d#%0*d#(%%*d,%%0*d传入5,a,5,a)\n\n",5,a,5,a);
                                                       /* #3 */
  /*标识符o,u,x,X设定方法一样 */
  printf("#%08o#%08u#%08X#(%%08o,%%08u,%%08X)\n",	\  &a,&a,&a);
                                                      /* #4 */

  /* float,double(%f,%e,%g) */
  printf("Floating point(f,e,g).....(ex: ff=0.01234567890)\n");
  printf("#%16f#(%%16f)\n",ff);   				/* #5 */
  printf("#%16.9f#(%%16.9f)\n",ff); 				/* #6 */
  printf("#%16.9e#(%%16.9e)\n",ff); 				/* #7 */
  printf("#%16.9g#(%%16.9g)\n",ff); 				/* #8 */
  printf("#%.9f#(%%.9f)\n",ff); 					/* #9 */
  printf("#%*.*e#(%%*.*f传入16,3,ff)\n\n",16,3,ff);	/* #10 */

  /* char(%c) */
  printf("char(c)...........(ex: 'a','b')\n");
  printf("#%5c#%05.3c#\n\n",'a','b'); 	/* #11 */

  /* char* 字符串(%s) */
  printf("char * 字符串(s)...(ex: str=\"123456\")\n");
  printf("#1234567890....对齐用\n");
  printf("#%10s#(%%10s)\n",str); 			/* #12 */
  printf("#%10.3s#(%%10.3s)\n",str); 			/* #13 */
  printf("#%5.3s#(%%5.3s)\n",str); 			/* #14 */
  printf("#%.*s#(%%.*s输入3,str)\n",3,str);	/* #15 */
  getchar();
}

程序执行结果：
int(d,i,o,u,x)........(ex: a=123)
#123#123# 123#(%2d,%3d,%4d)
#123#123#0123#(%02d,%03d,%04d)
#  123#00123#(%*d,%0*d传入5,a,5,a)

#31177000#06618624#0064FE00#(%08o,%08u,%08X)
Floating point(f,e,g).....(ex: ff=0.01234567890)
#        0.012346#(%16f)
#     0.012345679#(%16.9f)
# 1.234567890e-02#(%16.9e)
#    0.0123456789#(%16.9g)
#0.012345679#(%.9f)
#       1.235e-02#(%*.*f传入16,3,ff)
char(c)...........(ex: 'a','b')
#    a#    b#

char * 字符串(s)...(ex: str="123456")
#1234567890....对齐用
#    123456#(%10s)
#       123#(%10.3s)
#  123#(%5.3s)
#123#(%.*s传入3,str)