Jump to navigation Jump to search
Revision as of 19:23, 15 October 2009 by
_UNSIGNED defines a numerical value as being positive only in QB64 only.
- Syntax: _DEFINE LetterRange AS [_UNSIGNED] datatype
- Although _UNSIGNED values can use negative values the result subtracts from the highest value of the number's type keeping it positive.
- Datatype can be any of the following: INTEGER, SINGLE, DOUBLE, LONG, STRING, _BIT, _BYTE, _INTEGER64, _FLOAT
- _UNSIGNED can be used in a _DEFINE statement to set undefined variable name first letters as all positive only values.
- Can also be used in DIM statements or Subprocedure parameter definitions following AS.
- _UNSIGNED allows larger positive numerical variable value limits than signed ones.
- The Unsigned variable type suffix used is the tilde ~ before the number's own type suffix: variablename~&
Example 2: How negative values affect the _UNSIGNED value returned by a byte(8 bits).
- 00000001 - unsigned & signed are both 1
- 01111111 - unsigned & signed are both 127
- 11111111 - unsigned is 255 but signed is -1
- 11111110 - unsigned is 254 but signed is -2
- 11111101 - unsigned is 253 but signed is -3