在C語言ARM RVCT編譯器中將double轉換爲int

Question

我需要從雙變量中獲取最後四個字節。平臺是Arm和編譯器是RVCT。使用的編程語言是C.什麼是最安全的方法。

感謝

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;