程序中的所有数在计算机内存中都是以二进制的形式储存的。位运算就是直接对整数在内存中的二进制位进行操作。C语言中位运算符： &(按位与)、| (按位或)、~(按位取反)、 <<(左移)、>>(右移) 、^(异或运算)。

(资料图片仅供参考)

计算机所能识别的即为二进制数，位运算就是按位运算， 因而同等情况下位运算效率一般都高于其它方式。

unsigned char a=0x45,b=0x89; a=0x45(0100 0101) b=0x89(1000 1001)

~(取反)

<<(左移) >>(右移)

&按位与

^(按位异或)

|(按位或)

#include int main(){unsigned char a=0x45,b=0x89;printf("与运算a&b:%#xn",a&b);printf("或运算a|b:%#xn",a|b);printf("取反运算~a:%#xt ~b:%#xn",~a&0xff,~b&0xff);printf("左移a<<1:%#xt b<<1:%#xn",(a<<1)&0xff,(b<<1)&0xff);printf("右移a>>1:%#xt b>>1:%#xn",a>>1,b>>1);printf("异或a^b:%#xn",a^b);}[wbyq@wbyq 123]$ gcc main.c [wbyq@wbyq 123]$ ./a.out 与运算a&b:0x1或运算a|b:0xcd取反运算~a:0xba ~b:0x76左移a<<1:0x8a b<<1:0x12右移a>>1:0x22 b>>1:0x44异或a^b:0xcc

1.定义两个变量unsigned char a=0x45,b=0x89;将a的第6位清0，将b的第4位置1；

2.定义两个整型变量a,b将a,b的值交换位置(不借助第三个变量，使用位运算)；

3.定义一个整型变量data，将字符"a"、"b"、"c"、"d" 保存到data中，并输出字符abcd；

汉字显示我们每时每刻都在使用，那汉字是如何显示在屏幕上的呢？通过位运算的学习我们即可通过printf模拟函数输出显示。

例如我们需要在一个8*8的点阵方格中显示一个”中”字。可以看做如下：

一个有8个格子，刚好一个字节有8位，一个方格中有两个状态：空白和显红。我们可以把空白的地方看做0，把显示红色的地方看做1，这样整个8*8个格我们就可以用8个字节表示，坐标为高位，右边为低位，高位在前方式。表示如下：

第一行：0x08;

第二行：0x08;

第三行：0x3e;

第四行：0x2a;

第五行：0x2a;

第六行：0x3e;

第七行：0x08;

第八行：0x08;

通过位运算实现如下：

#include const unsigned char buff[]={0x08,0x08,0x3E,0x2A,0x2a,0x3e,0x08,0x08};int main(){int i,j;unsigned char temp;for(i=0;i<8;i++){temp=buff[i];for(j=0;j<8;j++)/*一个字节有8位数据*/{if(temp&0x80){printf("*");}else {printf(" ");}temp<<=1;//继续判断下一位数据}printf("n");}}

1.通过PCtoLCD2002工具实现汉字取模进行取模，封装汉字显示函数，以横向和纵向两种方式显示。

#include #define FONT_SIZE 24const char buf[][24*24/8]={{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x60,0x00,0x00,0x70,0x00,0x00,0x70,0x00,0x00,0x30,0x00,0x00,0x31,0xC0,0x00,0x7F,0xE0,0x0F,0xF0,0xE0,0x0E,0x30,0xE0,0x06,0x3F,0xC0,0x07,0xF9,0xC0,0x06,0x31,0x80,0x06,0x31,0x80,0x06,0xFF,0x00,0x03,0xF0,0x00,0x00,0x70,0x00,0x00,0x30,0x18,0x00,0x30,0x0C,0x00,0x38,0x1C,0x00,0x1F,0xFC,0x00,0x03,0xC0,0x00,0x00,0x00,0x00,0x00,0x00},/*"电",0*/{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x07,0x80,0x00,0x7D,0xC0,0x01,0xE3,0xC0,0x00,0x07,0x00,0x00,0x06,0x00,0x00,0x3C,0x00,0x00,0x1C,0x1C,0x00,0x0F,0xFE,0x0F,0xFC,0x00,0x3C,0x0E,0x00,0x00,0x0E,0x00,0x00,0x0E,0x00,0x00,0x0E,0x00,0x00,0x0E,0x00,0x00,0x0E,0x00,0x00,0x0E,0x00,0x00,0x0E,0x00,0x00,0xFC,0x00,0x00,0x3C,0x00,0x00,0x18,0x00,0x00,0x00,0x00},/*"子",1*/{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x18,0x00,0x00,0x1C,0x00,0x00,0x1C,0xF0,0x01,0x9C,0x30,0x01,0xD8,0x00,0x01,0x99,0xE0,0x03,0xBF,0x80,0x03,0xF0,0x00,0x03,0x30,0x00,0x00,0x73,0x80,0x00,0x7F,0xC0,0x00,0xF3,0x80,0x00,0xFB,0x80,0x01,0xDF,0x00,0x01,0x8F,0x00,0x03,0x07,0x00,0x07,0x0F,0x80,0x0E,0x39,0xE0,0x18,0x60,0xF8,0x00,0x00,0x7E,0x00,0x00,0x00,0x00,0x00,0x00},/*"发",2*/{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x1C,0x00,0x03,0x9C,0x00,0x03,0x0D,0xC0,0x03,0x0F,0x00,0x03,0x1E,0x60,0x03,0xF7,0xE0,0x33,0xE3,0xC0,0x1B,0x83,0xCC,0x1F,0x06,0xFC,0x03,0x1C,0x1C,0x03,0x00,0xE0,0x03,0x1F,0xC0,0x07,0x8D,0x80,0x07,0xCD,0x80,0x06,0xDD,0x80,0x0E,0x19,0x86,0x0C,0x31,0x86,0x18,0x71,0xCE,0x30,0xC0,0xFC,0x00,0x00,0x00,0x00,0x00,0x00},/*"烧",3*/{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x38,0x00,0x00,0x1C,0x00,0x00,0x18,0x00,0x00,0x38,0x00,0x00,0x3B,0xF0,0x03,0xFF,0x00,0x07,0xB0,0x00,0x00,0x70,0x00,0x00,0x60,0x00,0x00,0x6F,0xC0,0x00,0xFB,0x80,0x00,0xC3,0x80,0x01,0xF3,0x80,0x03,0xBB,0x00,0x03,0x0F,0x00,0x06,0x07,0x00,0x0C,0x0F,0x80,0x18,0x1D,0xC0,0x70,0x38,0xF0,0x01,0xE0,0x7F,0x00,0x00,0x00,0x00,0x00,0x00},/*"友",4*/};int main(){int i,j,k,x;unsigned char temp;for(i=0;i