对printf函数的理解1

看如下代码：

  #include <stdio.h>

  int main(int argc, const char *argv[])

  {

      printf("%s\n","peng","dopmg","石家庄铁道大学");

      return ;

  }

将代码改成：

 #include <stdio.h>

 int main(int argc, const char *argv[])

 {

     printf("%s%s%s\n","peng","dopmg","石家庄铁道大学");

     return ;

 }       

结果变成：

格式化输出：

 #include <stdio.h>

 #include <limits.h>

 int main(void)

 {

 unsigned char uc = UCHAR_MAX;

 unsigned short us = USHRT_MAX;

 unsigned int ui = UINT_MAX;

 unsigned long ul = ULONG_MAX;

 unsigned long long ull = ULLONG_MAX;

 puts("[output, specific values are implementation-dependent.]");

 printf("UCHAR_MAX, %u (decimal), %#o (octal), %#x (hex)\n",

 uc, uc, uc);

 printf("USHRT_MAX, %u (decimal), %#o (octal), %#x (hex)\n",

 us, us, us);

 printf("UINT_MAX, %u (decimal), %#o (octal),\n %#x (hex)\n",

 ui, ui, ui);

 printf("ULONG_MAX, %lu (decimal), %#lo (octal),\n %#lx (hex)\n",

 ul, ul, ul);

 printf

 ("ULLONG_MAX, %llu (decimal),\n %#llo (octal),\n %#llx (hex)\n",

 ull, ull, ull);

 puts("[end of output]");

 return ;

 }

 [output, specific values are implementation-dependent.]

 UCHAR_MAX,  (decimal),  (octal), 0xff (hex)

 USHRT_MAX,  (decimal),  (octal), 0xffff (hex)

 UINT_MAX,  (decimal),  (octal),

 0xffffffff (hex)

 ULONG_MAX,  (decimal),  (octal),

 0xffffffff (hex)

 ULLONG_MAX,  (decimal),

  (octal),

 0xffffffffffffffff (hex)

 [end of output]