A Level Computer Science OCR Practice Exam

X XOR X is equal to what?

1. True

2. False

3. Error

4. Undefined

The correct answer is: False

The expression X XOR X evaluates to false. This is a fundamental property of the exclusive OR (XOR) logical operation. XOR takes two boolean inputs and returns true if and only if exactly one of the inputs is true. When both inputs are the same, as in this case where both inputs are X, the condition for XOR to return true is not satisfied. Hence, when X is true XOR X, the result is false because both operands are true. Similarly, when X is false XOR X, the result is also false because both operands are false. Therefore, evaluating X XOR X yields false in both scenarios, confirming that the correct answer is indeed false.