day2
1、不同的进制

#include<stdio.h>

int main()
{   
    int a = 10;     //10进制
	int b = 010;    //8进制
	int c = 0x10;   //16进制
	int d = 0b1010; //2进制

	printf("%d %d %d %d\n", a, b, c, d);
	printf("%o %o %o %o\n", a, b, c, d);
	printf("%x %x %x %x\n", a, b, c, d);
	return 0;
	}

2、按位与、异或、逆反进行运算

#include<stdio.h>

int main()
{  
    char a = 67;
	char b = 0x54;
	char c = 0;
	c = a & b;
	printf("%x \n", c);
	c = a | b;
	printf("%x \n", c);
    c = a ~ b;
	printf("%x \n", c);
	return 0;
	}

3、位运算适合char,short,int,long int,long long;
不适合float,double,long double。
4、左移运算

#include<stdio.h>

int main()
{
    char a = 5;
	a = a  << 1;
	printf("%x\n", a);
	a = a << 1;
	printf("%x\n", a);
	a = a << 1;
	printf("%x\n", a);
	a = a << 1;
	printf("%x\n", a);
	return 0;
	}

5、按要求保留前四位不变，将后四位的值作出变化

#include<stdio.h>

int main()
{   
	char a = 0x20;
	a = a | 0x05;
	char ch = a;
	
	printf("%d\n", a);
	return 0;
}

6、一个例子

#include<stdio.h>

int Get1Bit(int x)
	int sum = 0;
	while (x != 0)
	{
		if (x & 0x01)//判断
		{
			sum += 1;
		}
		x = x >> 1;
	}
	
	return sum;
}
	int main()
	 {
	int x = 23;
	int sum = Get1Bit(x);
	printf("%d\n", sum);
	return 0;
}