最近经常见到这些unsigned char,short,int ,long的定义,有时真的不确定位长是多少 ,上网查,又话是跟编译器有关,没一个准确答案。于是只好自己找答案,其实用一个最简 单地方就可以知道其长度,就是用sizeof函数。于是我写了如下一段: unsigned char uint8 = 0; signed char int8 = 0; unsigned short uint16 = 0; signed short int16 = 0; unsigned int uint32 = 0; signed int int32 = 0; float fp32 = 0; double fp64 = 0; unsigned long ulong = 0; printf("unsigned char is %d bit\n\r", sizeof(uint8)*8); printf("signed char is %d bit\n\r", sizeof(int8)*8); printf("unsigned short is %d bit\n\r", sizeof(uint16)*8); printf("signed short is %d bit\n\r", sizeof(int16)*8); printf("unsigned int is %d bit\n\r", sizeof(uint32)*8); printf("signed int is %d bit\n\r", sizeof(int32)*8); printf("float fp32 is %d bit\n\r", sizeof(fp32)*8); printf("double fp64 is %d bit\n\r", sizeof(fp64)*8); printf("unsigned long is %d bit\n\r", sizeof(ulong)*8); signed char is 8 bit unsigned short is 16 bit signed short is 16 bit unsigned int is 32 bit signed int is 32 bit float fp32 is 32 bit double fp64 is 64 bit unsigned long is 32 bit 这个单词迷惑了。 不过,我又感到迷惑的是unsigned int 和unsigned long既然都是32位,那它们有什么区别 呢? |
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