Reverse integer bitwise without using loop

Question

I want to write a program which reverses the bits of an integer.
Ex 11000101 to 10100011
I know how to solve this using a loop, but I came across solutions that do it us

Answer 1

1100 0101

>> 4 means we are shifting the bits by 4 to the right:

0000 1100

<< 4 means we are shifting the bits by 4 to the left:

0101 0000

| is the or operation:

0000 1100 
↓↓↓↓ ↓↓↓↓ |
0101 0000
---------
0101 1100

As you see, the program changed the two blocks of 4 bits.