hibyte = Value >> 8是什么意思？

Question

I am using C for developing my program and I found out from an example code

unHiByte = unVal >> 8;

What does this mean?? If unVal = 250 . What could be the value for unHiByte ??

I am really confused with this..Please Help..

Thanks in advance..

Answer 1

">>" in programming is a bitwise operation. The operation >> means shift right operation. So unVal >> 8 means shift right unVal by 8 bits. shifting the bits to the right can be interpreted as dividing the value by 2.

Hence, unHiByte = unval >> 8 means unHiByte = unVal/(2^8) (divide unVal by 2 eight times)

Answer 2

Without going into the shift operator itself (since that is answered already), here the assumption is that unVal is a two byte variable with a high byte (the upper 8 bits) and a low byte (the lower 8 bits). The intent is to obtain the value produced by ONLY the upper 8 bits and discarding the lower bits.

The shift operator though should easily be learned via any book / tutorial and perhaps was the reason some one down voted the question.

Answer 3

The >> is a bitwise right shift .

It operates on bits. With unHiByte = unVal >> 8; When unVal=250 .

Its binary form is 11111010

Right shift means to shift the bits to the right. So when you shift 1111 1010 , 8 digits to right you get 0000 0000 .

Note: You can easily determine the right shift operation result by dividing the number to the left of >> by 2^(number to right of >> )

So, 250/2 ⁸ = 0