Logical operators Foundation

All logical operators execute logical operations and return logical values. There is one unary logical operator and two binary operators. The unary logical operator performs negation. There are two syntaxes that can be used for it. The table below lists all logical operators:

The operands of the logical operators must be of the logical data type, which means they must result in the value .T. (true) or .F.(false). The following code shows various combinations of operands for logical operators and the results of the operations:

? .NOT. (.T.)               // result: .F. 
? ! (.F.)                   // result: .T. 
? (.T.) .AND. (.T.)         // result: .T. 
? (.F.) .AND. (.T.)         // result: .F. 
? (.F.) .AND. (.F.)         // result: .F. 
? (.T.) .AND. (.F.)         // result: .F. 
? (.T.) .OR.  (.T.)         // result: .T. 
? (.T.) .OR.  (.F.)         // result: .T. 
? (.F.) .OR.  (.T.)         // result: .T. 
? (.F.) .OR.  (.F.)         // result: .F.