Revision [17287]

This is an old revision of KeyPgStatic made by CountingPine on 2014-09-23 11:24:17.

 

STATIC


Defines variables, objects and arrays having static storage

Syntax:
Static symbol1 [ (array-dimensions) ] KeyPgAs As DataType DataType [ = expression] [, symbol2 [ (array-dimensions) ] KeyPgAs As DataType DataType [ = expression], ...]
or
Static KeyPgAs As DataType DataType symbol1 [ (array-dimensions) ] [ = expression] [, symbol2 [ (array-dimensions) ] [ = expression], ...]

or

KeyPgSub Sub|KeyPgFunction Function procedurename ( parameters ) [KeyPgAs As DataType DataType] Static
...
KeyPgEndblock End KeyPgSub Sub|KeyPgFunction Function

Parameters:
symbol
variable or array symbol name.
array-dimensions
lower-bound KeyPgTo To upper-bound [, ...]
or
KeyPgAny Any [, KeyPgAny Any...]
or empty.
expression
An constant expression, or an array of constant expressions

Description:
Specifies ProPgStorageClasses 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 ProPgLiterals numeric literals, KeyPgConst constants or KeyPgEnum enumerations may be used as subscript range values. Static variable-length arrays must be declared empty (no subscript range list) and resized using KeyPgRedim Redim before used.
In both iterative and recursive blocks, like looping CatPgControlFlow 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 ProPgStorageClasses static storage for all local variables, objects and arrays.

At module-level variable declaration only, the modifier KeyPgShared 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 KeyPgStaticMember static member procedures or variables.

Examples:
Sub f
    '' times called is initially 0
    Static timesCalled As Integer = 0
    timesCalled += 1
    Print "Number of times called: " & timesCalled
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:
See also:
Back to Procedures
Back to Variable Declarations
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