Invert 1 bit in C#
I have 1 bit in a byte
(always in the lowest order position) that I'd like to invert.
ie given 00000001 I'd like to get 00000000 and开发者_Python百科 with 00000000 I'd like 00000001.
I solved it like this:
bit > 0 ? 0 : 1;
I'm curious to see how else it could be done.
How about:
bit ^= 1;
This simply XOR's the first bit with 1, which toggles it.
If you want to flip bit #N, counting from 0 on the right towards 7 on the left (for a byte), you can use this expression:
bit ^= (1 << N);
This won't disturb any other bits, but if the value is only ever going to be 0 or 1 in decimal value (ie. all other bits are 0), then the following can be used as well:
bit = 1 - bit;
Again, if there is only going to be one bit set, you can use the same value for 1 as in the first to flip bit #N:
bit = (1 << N) - bit;
Of course, at that point you're not actually doing bit-manipulation in the same sense.
The expression you have is fine as well, but again will manipulate the entire value.
Also, if you had expressed a single bit as a bool
value, you could do this:
bit = !bit;
Which toggles the value.
More of a joke: Of course, the "enterprisey" way would be to use a lookup table:
byte[] bitTranslations = new byte[256];
bitTranslations[0] = 1;
bitTranslations[1] = 0;
bit = bitTranslations[bit];
Your solution isn't correct because if bit == 2 (10) then your assignment will yield bit == 0 (00).
This is what you want:
bit ^= 1;
精彩评论