C语言 如何通过printf打印二进制数
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How to print binary number via printf
提问by Registered User
Possible Duplicate:
Is there a printf converter to print in binary format?
可能的重复：
是否有 printf 转换器以二进制格式打印？
Here is my program
这是我的程序
#include<stdio.h>
int main ()
{
int i,a=2;
i=~a;
printf("a=%d\ni=%d\n",a,i);
return 0;
}
The output is
输出是
a=2
i=-3
I want this to print in binary. There are %x, %o, and %d which are for hexadecimal, octal, and decimal number, but what is for printing binary in printf?
我希望这个以二进制打印。有 %x、%o 和 %d 分别用于十六进制、八进制和十进制数，但是在 printf 中打印二进制是什么？
回答by Vinicius Kamakura
printf() doesn't directly support that. Instead you have to make your own function.
printf() 不直接支持。相反，您必须创建自己的函数。
Something like:
就像是：
while (n) {
if (n & 1)
printf("1");
else
printf("0");
n >>= 1;
}
printf("\n");
回答by zw324
Although ANSI C does not have this mechanism, it is possible to use itoa() as a shortcut:
尽管 ANSI C 没有这种机制，但可以使用 itoa() 作为快捷方式：
char buffer [33];
itoa (i,buffer,2);
printf ("binary: %s\n",buffer);
Here's the origin:
这是起源：
It is non-standard C, but K&R mentioned the implementation in the C book, so it should be quite common. It should be in stdlib.h.
它是非标准的C，但K&R在C书中提到了实现，所以它应该是很常见的。它应该在 stdlib.h 中。
