numericNOptional
Positive or negative integer and decimal numeric values.
FOUNDATIONPublished
Data typing in AdvPL
Local <variável> As <tipo> · Function <nome>(<parâmetro> As <tipo>) As <tipo>Declare variable, parameter, return, property and method types to make inconsistencies more visible.
Overview
AdvPL is dynamically typed, but explicit types may be declared in .PRW source files. These annotations help the compiler and AppServer identify incompatible assignments, parameters and return values. Documented types are numeric, character, date, codeblock, logical, array, object and variadic. TLPP typing has its own features and documentation.
Syntax
Local <variável> As <tipo> · Function <nome>(<parâmetro> As <tipo>) As <tipo>Parameters
character / charCOptional
Character strings.
dateDOptional
Date values.
codeblock / blockBOptional
Code blocks that can be evaluated at runtime.
logicalLOptional
True (.T.) or false (.F.) logical values.
arrayAOptional
Arrays that can contain values and structures.
objectOOptional
Class instances or interface objects.
variadicHOptional
A variable number of function parameters.
Typed local variables
User Function ExTypes()
Local cMessage As Character
Local nQuantity As Numeric
Local dToday As Date
Local lActive As Logical
Local aItems As Array
cMessage := "Registration available"
nQuantity := 3
dToday := Date()
lActive := .T.
aItems := {"A", "B", "C"}
If lActive
MsgInfo(cMessage + " - items: " + CValToChar(nQuantity))
EndIf
ReturnExpected result
Each variable declares its expected type, making incompatible assignments easier to identify.
Typed parameter and return
User Function OrderTotal(nValue As Numeric, nQuantity As Numeric) As Numeric
Local nTotal As Numeric
nTotal := nValue * nQuantity
Return nTotalExpected result
The prototype documents that both parameters and the return value are numeric.
Class property and method
Class Pedido
Data nTotal As Numeric
Method New(nValor As Numeric) As Object
EndClass
Method New(nValor As Numeric) Class Pedido
::nTotal := nValor
Return SelfExpected result
The property, parameter and constructor return have declared types.
Detectable incompatibility
User Function ExIncompativel()
Local cCodigo As Character
Local nTotal As Numeric
nTotal := "ABC"
cCodigo := 10
ReturnExpected result
The compiler may issue warning W0015 for incompatible C and N conversions. Correct the source or convert the value deliberately.
- Use As <type> on local variables, parameters, function returns, class properties and methods.
- Explicit typing improves routine contracts and allows the compiler to report incompatibilities.
- For typed calls, AppServer also compares the received type with the defined prototype.
- The official reference lists historical requirements from December 2014; confirm behavior in the version in use.
- Do not ignore compilation warnings: assigning character to numeric or vice versa conflicts with the declared contract.
- According to the documentation, an incompatible argument may reach the routine as NIL, produce a console warning and alter the expected flow.
- Do not confuse .PRW typing with TLPP (.tlpp) typing, which has separate features and documentation.
- Explicit typing does not replace validation of NIL, content, ranges and business rules.