numericVariable -= valueToSubtract
This statement decrements
intVar by 1 (or by
valueToSubtract); that is, it subtracts 1 from the value of
intVar, and stores the value back into
intVar must be a (signed or unsigned) byte variable, short-integer variable or long-integer variable. If
intVar is already at the minimum value for its variable type, then
dec(intVar) will cycle it back to its maximum value. As of Release 3, FutureBasic supports the use of -= to decrease the value of a variable by a specified amount.
x& -= 1
...are all equivalent to:
x& = x& - 1
The following expressions are also equivalent:
x& = x& - 100
x& -= 100
-= syntax may not be used for arrays of strings, containers, or records where arrays are involved, only numeric values may take advantage of this syntax.
inc; dec long/word/byte