Q88746: Difference Between Macro Substitution and Named Expression

Article: Q88746
Product(s): Microsoft FoxPro
Version(s): MS-DOS:2.0,2.5,2.5a; WINDOWS:2.5,2.5a,3.0
Operating System(s): 
Keyword(s): 
Last Modified: 02-FEB-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
- Microsoft FoxPro for MS-DOS, versions 2.0, 2.5, 2.5a 
- Microsoft FoxPro for Windows, versions 2.5, 2.5a 
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SUMMARY
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Macro substitution and name expressions are both methods used to place the value
of a variable in a FoxPro command. The fundamental difference between the two is
that with name expressions, the value of the variable is substituted before
execution. With macro substitution, the value is substituted during execution.

MORE INFORMATION
================

The FoxPro language compiler parses the program and replaces a name expression
with the value during the first pass; from that point on, only the value, not
the variable, is used. The FoxPro compiler leaves a macro substitution as a
reference to the variable that is not resolved until the program is executed.

If you use a name expression and the variable changes during execution, the new
value of the variable is not used. However, if you use a macro substitution, the
new value will be substituted.

Additional query words: VFoxWin FoxWin FoxDos

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Keywords          :  
Technology        : kbVFPsearch kbAudDeveloper kbFoxproSearch kbZNotKeyword3 kbFoxPro200DOS kbFoxPro250DOS kbFoxPro250aDOS kbFoxPro250 kbFoxPro250a kbVFP300
Version           : MS-DOS:2.0,2.5,2.5a; WINDOWS:2.5,2.5a,3.0

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