Boolean Operators

Computer Science: OCR A Level, topic 4.3.3

Boolean Operators

Boolean operators perform logical operations on boolean variables and always return another boolean variable.

AND

AND

AND evaluates to True (1) if and only if both operands are True (1).
'.' is the symbol for the AND operator.

OR

OR evaluates to True (1) if any of the two operands are True (1).
'+' is the symbol for the OR operator.

NOT (negation)

NOT (negation)

NOT negates a logical value.
The symbol for the NOT operator is a line above the variable.
For example, NOT $A$ is written as $\overline{A}$ .

XOR

XOR

XOR means 'exclusive OR'.
The symbol for the XOR operator is $\bigoplus$ .

NAND

NAND

NAND means NOT AND.
$A$ NAND $B$ is written as $\overline{A.B}$ .

NOR

NOR

NOR means NOT OR.
$A$ NOR $B$ is written as $\overline{A+B}$ .

Test yourself on Boolean Operators

Which Boolean operator takes only one value as input?
What does the operation 0 NAND 0 evaluate to?

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