Bitwise Manipulation Functions

Possible Duplicate:
How do you set, clear and toggle a single bit in C?

I'm studying for an upcoming final and I want to verify some questions from the study guide.

Some context:

The Set() function sets a bit in a byte to 1

The Unset() function sets a bit in a byte to 0

The Flip() function "flips" the bit to the opposite of what it is

So some kid in our class took it upon himself to answer the study guide questions but I've already found some errors, and these answers sound fishy. Here's what he said:

Which operation is used for the Set? the or operator |

Which operation is used for the Unset? Xor operator ^ Done twice

Which operation is used for the Flip? Xor operator ^

Are these the correct bitwise operators to implement in the functions I've described above?

---

Set uses or

Unset uses And

Flip uses Xor

this was already answered here: How do you set, clear, and toggle a single bit?

---

你是对的第一个，但对于Unset()你应该使用&与0在该位

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    00000000 |
    00000001 =
--------------
    00000001   // Sets

    00000001 &
    00000000 =
--------------
    00000000   // Unsets

    00000001 ^
    00000001 =
--------------
    00000000   // Flips

如果bit是要在字节中处理的位：

x |= (1 << bit);    // Sets
x &= ~(1 << bit);   // Unsets   00000001 becomes 11111110.
x ^= (1 << bit);    // Flips

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