在C语言ARM RVCT编译器中将double转换为int

Question

我需要从双变量中获取最后四个字节。平台是Arm和编译器是RVCT。使用的编程语言是C.什么是最安全的方法。

感谢

Answer 1

int lastFour = *(((char*) &origDouble) + sizeof(double) - 4) 

Answer 2

double dval = 3.14159; 

// as an int 
uint32_t ival = *(uint32_t*)&dval; 

// as bytes 
uint8_t *all_bytes = (uint8_t*)&dval; 

uint8_t *last_four_bytes = all_bytes + 4;