在C中将两个数字转换为一个

Question

新手问题；我有两个二进制数；比如说； 0b11 和 0b00。我怎样才能将这两个数字组合起来，以便得到 0b1100(即将它们彼此紧挨着放置以形成一个新数字)

Answer 1

使用移位和或运算符:

unsigned int a = 0x03;  /* Binary 11 (actually binary 00000000000000000000000000000011) */
unsigned int b = 0x00;  /* Binary 00 */

/* Shift `a` two steps so the number becomes `1100` */
/* Or with the second number to get the two lower bits */
unsigned int c = (a << 2) | b;

/* End result: `c` is now `1100` binary, or `0x0c` hex, or `12` decimal */