C# bit test (Byte): check whether the 4th bit from the right (value 8) is ON. Which condition is correct?

Introduction / Context:
Testing whether a particular bit is set is a standard bitwise task. Here we need to test the 4th bit from the right (value 8) of a byte variable n.

Given Data / Assumptions:

• n is byte.
• Target bit is the 4th from the right (1-based), value 8.
• We must write a correct if-condition and message.

Concept / Approach:
To test if a bit is ON, AND the value with a mask that has 1 at that bit. If the result equals the mask, the bit is set. Therefore, use mask 8 and compare with 8.

Step-by-Step Solution:

Verification / Alternative check:
Try n = 13 (00001101). (n & 8) == 8 is true; try n = 5 (00000101), also true; try n = 1, false.

Why Other Options Are Wrong:

• A: Uses 16, which targets the 5th bit.
• C: Uses the invalid operator ! with a number.
• D: XOR comparison equals 8 only for specific values; it is not a generic bit test.
• E: ~ is bitwise complement; expression is invalid and meaningless for this test.

Common Pitfalls:
Mixing up XOR and AND for bit testing; confusing 0-based with 1-based bit positions.

Final Answer:
if ((n & 8) == 8) Console.WriteLine('Fourth bit is ON');