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$LET is a precompiler command, which is now usable by modern day cavemen to help include and exclude which sections of code compiles in their program based on OS/bit-size or other predefined conditions.


$LET variable = expression


  • Unlike LET, $LET is not optional.
  • $LET a = 12 sets a precompiler variable "a" to the value of 12. This variable is only valid for the precompiler itself and does nothing to affect the values of any variable/constant which might also be called "a" in the program.
  • Variable names can contain numbers, letters, and periods in any order. $LET 3.2 = TRUE is a perfectly valid variable and expression.
  • Expressions can contain one set of leading and/or trailing quotes; and any number of numbers, letters, and periods, in any order. $LET 3.2 = "TRUE" is also perfectly valid, but $LET 3.2 = ""TRUE"" will error because of the double quotes.
  • You can check a precompiler variable against special values DEFINED and UNDEFINED, in order to assess whether the variable has already been assigned a value. Useful for code in libraries which may be repeated.


  • See example 1 in $IF.

See also

Keyword Reference - Alphabetical
Keyword Reference - By Usage
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