C-switch case之如何巧妙判断范围区域

当判断整数时

• 示例: 判断整数范围

#include <stdio.h>

int main()
{
    unsigned char buf[]={0x00,0x07,0x11,0x60,0x61,0x66};

    for(int i=;i<;i++)
    switch(buf[i])
    {
        case 0x00 ... 0x10: printf("buf[%d] is 0x0 ~0x10\n",i);  break;
        case 0x11 ... 0x20: printf("buf[%d] is 0x11~0x20\n",i);  break;
        case 0x30 ... 0x60: printf("buf[%d] is 0x30~0x60\n",i);  break;
        case 0x61 ... 0xff: printf("buf[%d] is 0x61~0xff\n",i);  break;
    }
} 

打印:

当判断字符时

• 示例: 将"0x00"~"0xff"转化为数值0x00~0xff

#include <stdio.h>

int main()
{
    char buf[][]={"0xff","0X02","0X1f","0xf1","0xa1","0Xb0"};
    for(int i=;i<;i++)
    if(buf[i][]==''&&(buf[i][]=='x' || buf[i][]=='X'))    //匹配前缀
    {
        unsigned char val=;
        int err=;
        for(int j=;j<;j++)
        switch(buf[i][j])
        {
            case '' ... '' :   val= val* + (buf[i][j]-''); break;
            case 'a' ... 'f' :   val= val* + (buf[i][j]-'a'+); break;
            case 'A' ... 'F' :   val= val* + (buf[i][j]-'A'+); break;
            default :  err =;  break;
        }   
        if(!err)
            printf("buf[%d]  = 0X%02X\n",i,val);
        else
            printf("buf[%d]  ERR \n",i);
    }
    else
        printf("buf[%d]  ERR \n",i); 

} 

打印: