简单c语言问题 win8 vc6.0环境

[t514901334]

char receive[10] ="\x12\x34\xFF\x56\x78";

if(receive[2] == 0xFF)//为什么该式为假
{
printf("ok\n");//无ok输出。。。？
}

[relaxisland]

因为 0xFF默认是 int型 所以 receive[2] 从char 提升成int后，进行比较操作 提升到int 是0xFFFFFFFF 即-1 因此不等于0x000000FF,即256 解决办法可以把char数组声明成unsigned char 或者把0xFF强转成 char后进行比较

[worldy]

char 改为 unsigned char

[图灵狗]

改为if((unsigned char)receive[2] == 0xFF)

引用 楼主 t514901334 的回复:

char receive[10] ="\x12\x34\xFF\x56\x78"; if(receive[2] == 0xFF)//为什么该式为假 { printf("ok\n");//无ok输出。。。？ }