Variable
scope

Scope determines where a variable can be accessed and how long its value remains available during execution.

EXPLICIT DECLARATION

Local nNumero := 10

The identifier states that nNumero belongs to the function local scope.

SCOPEVISIBILITYLIFETIME

LOCALOnly the declaring routineUntil the function returns STATICDepends on declaration locationWhile the environment is running PRIVATEDynamic scopeUntil the creating function returns PUBLICGlobal, unless hidden by a PrivateUntil execution ends

SILENT ERROR

One letter can create another variable

When assigning to an unknown name, AdvPL may create a `PRIVATE` variable. If a declared variable is mistyped, the incorrect name may be treated as a new variable, changing the logic without the expected error.

Local nTotal := 100
nTotla := 50 // mistyped name: may create a Private

LOCAL

Current function

Created on each function activation. Recursive calls receive independent sets of local variables.

Visibility: Only the declaring routine
Lifetime: Until the function returns

EXAMPLE

User Function Pai()
    Local nVar := 10
    Filha()
Return .T.

Static Function Filha()
    // nVar is not visible here
Return

STATIC

Routine or file

Inside a function, it remains restricted to that routine and retains its value between calls. Outside routines, it can be accessed in the current source file.

Visibility: Depends on declaration location
Lifetime: While the environment is running

EXAMPLE

User Function Contador()
    Static nChamadas := 0
    nChamadas++
    ConOut(nChamadas)
Return

PRIVATE

Creating function and descendant calls

It may be declared or created implicitly by assignment. A Private with the same name in a called function temporarily hides the previous one.

Visibility: Dynamic scope
Lifetime: Until the creating function returns

EXAMPLE

User Function Pai()
    Private nVar := 10
    Filha()
Return .T.

Static Function Filha()
    ConOut(nVar) // 10
Return

PUBLIC

Entire environment

Remains available after the creating function returns. Without explicit initialization, its value is logical false (.F.).

Visibility: Global, unless hidden by a Private
Lifetime: Until execution ends

EXAMPLE

User Function CriarStatus()
    Public lSistemaAtivo := .T.
Return

User Function ConsultarStatus()
    ConOut(lSistemaAtivo)
Return

BEST PRACTICE

Declare your intent

Prefer `LOCAL` for temporary data and `STATIC` when state truly needs to be retained. Use `PRIVATE` and `PUBLIC` only when dynamic or global visibility is part of the routine design.

REFERENCES

SILVA, Waterloo Ferreira da. A Linguagem AdvPL. 2004, p. 22-24. Content summarized and reviewed; examples adapted.
TOTVS. Variable Context within a Program. TDN.
TOTVS. Creating and Assigning Variables. TDN.
TOTVS. Microsiga Protheus SDK. TDN — additional reference.

Page created on 01/08/2026 at 16:49

Variablescope

LOCAL

STATIC

PRIVATE

PUBLIC

Declare your intent

Variable
scope