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