How to concatenate 2 binary numbers?

Question

I have 2 integer values , x and y. x is 2 bits, and y is 10 bits . I need to find z , which is concatenation of x and y. z is 12 bits. How do I do that in java? I'd also appreciate if you could explain the logic behind that. Thanks.

Answer 1

Assuming x is to be the high-order part of the result:

int z = (x << 10) | y;

In other words, y is used directly as bits 0 to 9 of the result, and we shift x so that its value is in bits 10 and 11. Then we combine those two.

(Bits numbered from 0 at the least significant end)