Static
Defines variables, objects and arrays having static storage
Static symbol [ ( [ subscripts ] ) ] [ As DataType ] [ , ... ]
symbol
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.
When used with module-level and member procedure declarations, Static specifies static storage for all local variables, objects and arrays.
Static (Member) is also used in member procedure declarations to specify static member procedures.
Will output:
Syntax
Static symbol [ ( [ subscripts ] ) ] [ As DataType ] [ , ... ]
or
{ Sub|Function } proc_header Static[ ... ]
End { Sub|Function }Parameters
symbol
variable or array symbol name.
subscriptsa comma-separated list of subscript ranges.
proc_headerprocedure header for a procedure definition.
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.
When used with module-level and member procedure declarations, Static specifies static storage for all local variables, objects and arrays.
Static (Member) is also used in member procedure declarations to specify static member procedures.
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()
'' 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.
- Using Static to specify static member procedures is new to FreeBASIC.
See also
