QDS Operators

Edit Element, Skip Element, and Automatic Variable Element calculations may include logical or expression operators.

Logical Operators

There are three logical operators: AND (&), OR ( | ), and NOT (^). They work as follows:

AND (&)

• YES & YES evaluates to YES
• YES & NO evaluates to NO
• YES & MAYBE evaluates to MAYBE
• NO & YES evaluates to NO
• NO & NO evaluates to NO
• NO & MAYBE evaluates to NO
• MAYBE & YES evaluates to MAYBE
• MAYBE & NO evaluates to NO
• MAYBE & MAYBE evaluates to MAYBE

OR (|)

• YES | YES evaluates to YES
• YES | NO evaluates to YES
• YES | MAYBE evaluates to YES
• NO | YES evaluates to YES
• NO | NO evaluates to NO
• NO | MAYBE evaluates to MAYBE
• MAYBE | YES evaluates to YES
• MAYBE | NO evaluates to MAYBE
• MAYBE | MAYBE evaluates to MAYBE

NOT (^)

• ^ YES evaluates to NO
• ^ NO evaluates to YES
• ^ MAYBE evaluates to MAYBE

Mathematical and Relational Operators

In conditional expressions or calculations, you can use any combination of values and the following mathematical and relational operators.

Operator	Description
+	Addition
-	Subtraction
*	Multiplication
/	Division
=	Equal to
<	Less than
<=	Less than or equal to
>	Greater than
>=	Greater than or equal to
^=	Not equal to

Special Codes

To refer to Special Code values in expressions use the following:

• Don't Know = .DK
• Refused = .REF
• Not Applicable = .NA
• Skipped = .SK.
• Missing (Automatic Variables) = .MSG
• Missing (Data Elements) = .

For example, VAR1 = .DK or VAR2 ^= .REF