Category : Dbase (Clipper, FoxBase, etc) Languages Source Code
Archive   : TN8911.ZIP
Filename : GROUPS1.TXT

 
Output of file : GROUPS1.TXT contained in archive : TN8911.ZIP
A Word on Macro Substitution for the Truly Innocent
The ampersand (&) is the indirection symbol in the dBASE language (in dBASE we
call it Macro Substitution because we came up with the idea before "Macro"
came to mean "keystroke replay").

Indirection or "macro substitution" tells dBASE to substitute the value of the
variable and use that value as a variable.

So, if we say a=2 and b=3, we can say c=a+b and the system sees it as c=2+3 or
c=5. If we add to it d="a" and c=&d, the system first substitutes the
value of d in the last equation making it c=a, then reevalutaes the equation
(c=2).

The KeyWord example makes use of macro substitution in the line
REPLACE &m_Field_Name WITH "x"
M_Field_Name holds the name of the field that was added to the database. At
the time the program is coded, the programmer has no way of knowing what the
name of the new field will be, but knows that the name will be stored in the
variable, m_Field_Name. Using the ampersand she can tell dBASE to go check

m_Field_Name to find out where to REPLACE the "x".



  3 Responses to “Category : Dbase (Clipper, FoxBase, etc) Languages Source Code
Archive   : TN8911.ZIP
Filename : GROUPS1.TXT

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/