Defines variables, objects and arrays having static storage
Syntax
Parameters
symbol
variable or array symbol name.
array-dimensions
lower-bound To upper-bound [, ...]
or
Any [, Any...]
or empty.
Description
Specifies
static storage for variables, objects and arrays; they are allocated at program startup and deallocated upon exit. Objects are constructed once when they are defined, and destructed upon program exit.
When declaring static arrays, only
numeric literals,
Constants or
Enumerations may be used as subscript range values. Static variable-length arrays must be declared empty (no subscript range list) and resized using
ReDim before used.
In both iterative and recursive blocks, like looping
control flow statements or procedures, static variables, objects and arrays local to the block are guaranteed to occupy the same storage across all instantiations of the block. For example, procedures that call themselves - either directly or indirectly - share the same instances of their local static variables.
A static variable may only be initialised with a constant value: its starting value is set at the start of the program before any code is run, and so it cannot depend on any variables or functions in it.
When used with module-level and member procedure declarations,
Static specifies
static storage for all local variables, objects and arrays.
At module-level variable declaration only, the modifier
Shared may be used with the keyword
Static to make module-level static variables visible inside procedures.
When used with in a user-defined type,
Static creates
Static Member Procedures Or Variables.
Example
Sub f
'' static variables are initialized to 0 by default
Static i As Integer
i += 1
Print "Number of times called: " & i
End Sub
'' the static variable in f() retains its value between
'' multiple procedure calls.
f()
f()
Will output:
Number of times called: 1
Number of times called: 2
Differences from QB
- QuickBASIC allows variables and arrays to be declared using the Static keyword within procedures and DEF FN routines only.
- Static forces local visibility of variables and arrays in QuickBASIC DEF FN routines. FreeBASIC supports neither DEF FN routines nor this usage of Static.
See also