I've been trying to figure out bitwise operators again today, and some things are still a little fuzzy to me. Everything made sense until I started trying to combine the | operator with ~, for instance: number | ~number. On a side note, I already read the wikipedia article on the two's complement, and understand that aspect of it (I think).
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| 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 |
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| 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | = 7
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| 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | = ~5 or -6
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Using the & operator like 7 & ~5 yields the expected result of 2, as only the 2 column is set in both rows. What's getting me here is that 7 | ~5 is outputting -1. I'd expect that would either be 255, because every column has a 1 in it, or 5, because the bottom row might count 0s instead of 1s. But it's neither of those, it's -1.
I've googled this until my brain hurts, and I can't find one single article anywhere that addresses this. Does anyone know what's going on here?
The result of 7 | ~5 is a bit pattern of all ones. That's -1 in two's complement.