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5.9.4 Values

A Value behaves like a Constant, but it can be changed. TO is a parsing word that changes a Values. In Gforth (not in Standard Forth) you can access (and change) a value also with >body.

Here are some examples:

12 Value APPLES     \ Define APPLES with an initial value of 12
34 TO APPLES        \ Change the value of APPLES. TO is a parsing word
1 ' APPLES >body +! \ Increment APPLES.  Non-standard usage.
APPLES              \ puts 35 on the top of the stack.
Value ( w "name" –  ) core-ext “Value”
TO ( value "name" –  ) core-ext “TO”

changes the value of name to value

+TO ( value "name" –  ) gforth-1.0 “+TO”

increments the value of name by value

addr ( "name" – addr  ) gforth-1.0 “addr”

provides the address addr of the value stored in name