# Logical operators in expressions

Logical operators determine the validity of one or more statements. The operators return a value of 1 (or another non-zero value) if the expression is true, or a value of 0 if false. There are three logical operators: AND, OR, and NOT.

Symbols | Operator | Example
AND, && | and | (tag1 < tag 2) AND (tag1 == 5)
OR, || | or | (tag1 == 5) OR (tag1 ==10)
NOT | negation | NOT(tag1 > tag2)

Tip: | The parentheses are essential in the above expressions. Any statement which evaluates to a non-zero value is regarded as true. For example, the statement tag1 will be false if the value of tag1 is 0, and true if tag1 has any other value.

## See also

About expressions

Example: Logical operators

Logical AND

Logical OR

Logical NOT