Tag Archives: OR

.OR. Logical OR

Posted on by vivaclipper 
.OR.
 Logical OR--binary                              (Logical)
------------------------------------------------------------------------------
 Syntax

     <lCondition1> .OR. <lCondition2>

 Type

     Logical

 Operands

     <lCondition1> and <lCondition2> are logical expressions.

 Description

     The .OR. operator is a binary logical operator that executes a logical
     OR operation using the following modified Boolean rules:

     .  Returns true (.T.) if either <lCondition1> or <lCondition2>
        evaluates to true (.T.)

     .  Returns false (.F.) if both <lCondition1> and <lCondition2>
        evaluates to false (.F.)

     Warning!  In a departure from the Summer '87 and other dialect
     behavior, Clipper shortcuts the evaluation of .OR. operands.  This
     means that <lCondition1> and <lCondition2> are both evaluated only when
     <lCondition1> evaluates to false (.F.).  If <lCondition1> evaluates to
     true (.T.), the .OR. operation is true (.T.) and <lCondition2> is,
     therefore, not evaluated.  For backward compatibility, shortcutting can
     be suppressed by compiling with the /Z option.

 Examples

     .  This example shows .OR. results using different operands:

        ? .T. .OR. .T.            // Result: .T.   (shortcut)
        ? .T. .OR. .F.            // Result: .T.   (shortcut)
        ? .F. .OR. .T.            // Result: .T.
        ? .F. .OR. .F.            // Result: .F.

See Also: .AND. .NOT.

 

Introduction Number and Bit Manipulation

Posted on by vivaclipper

Introduction CT Number and Bit Manipulation

This module discusses number and bit manipulation. Specifically, the numeric section deals with conversions between two different number systems, and the creation of random numbers.

The bit manipulation section covers such required binary operations as AND, OR, XOR, and NOT, and how to test, set and clear bits. The NUMLOW() and NUMHIGH() functions are important for CA-Clipper Tools functions that take two 8-bit values and return them as combined 16-bit numbers. An example is the GETCURSOR() function from the Extended Drivers module.

Many of the functions in this module have a <value> parameter type. In this case, a number can be in the range of 0 to 65535 (or 4 294 967 295) and/or a hexadecimal string in the range of “0000” to “FFFF” (or “FFFFFFFF”).

CT Number and Bit Manipulation Functions