<pre name="code" class="cpp">
方法一
#include<stdio.h>
#include<math.h> void bit_set(unsigned char *p_date, unsigned char position, int flag)
{
char a =(char) pow(2, (position - 1)); //指数 2^(position - 1)
if (flag == 1)
{
*p_date |= a;//0000 0010或0000 0001 |表示按位或
} // 0000 0011
else
{
*p_date &= ~a; //0000 0010&1111 1110 ~表示按位取反
} // 0000 0010 &表示按位与 } int main()
{
unsigned char val = 2;
bit_set(&val, 1, 0);
printf("%d\n", val);
getchar();
return 0;
}
方法二
#include<stdio.h> void bit_set(unsigned char *p_date, unsigned char position, int flag)
{
if (flag == 1)
{
*p_date |= (1 << (position - 1));//0000 0010或0000 0001
} // 0000 0011
else if (flag = 0)
{
*p_date &= ~(1 << (position - 1));//0000 0010&1111 1110
} // 0000 0010 } int main()
{
unsigned char val = 2;
bit_set(&val, 1, 0);
printf("%d\n", val);
getchar();
return 0;
}
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