如何在一个十六进制值中合并4个无符号char数组元素？

Question

我有一个由4个元素组成的数组，类型为unsigned char。如何将它们合并为一个十六进制值？我需要将此值转换为IEE754值。

例如unsigned char arr[]={0x41,0xD9,0xD4,0x03}

预期o / p：0x41D9D403

Answer 1

unsigned long hex_val = ((unsigned long)arr[0] << 24) | ((unsigned long)arr[1] << 16) | ((unsigned long)arr[2] << 8) | ((unsigned long)arr[3]);