Logical Expressions 

When writing application programs, you often need to formulate conditions. These are used mostly in control structures, or serve to decide whether to exit a processing block. Conditions use logical expressions that may be either true or false.

Note: Since Release 6.10 it is possible to use not only data objects but also return values of built-in functions and function methods at the operand positions of logical expressions.

Comparing Data Objects

Logical expressions can be used as comparisons in the form:

... operand1 operator operand2 ...

Depending on which data type the operands operand1 and operand2 are, different logical relational operators can be used.

·        Relational Operators for Operands of All Data Types

·        Relational Operators for Character-Type and Byte-Type Data Types

·        Relational Operators for Bit Templates

Other Logical Expressions

Along with operand comparisons, you can formulate logical expressions that check whether the operands meet certain requirements:

Combining Several Logical Expressions

Several logical expressions can be linked with a condition.