Menggunakan Prosedur dan Fungsi

Berikut ini dijelaskan penggunaan-penggunaan dasar untuk prosedur dan fungsi di dalam LibreOffice Basic.

Ikon Catatan

When you create a new module, LibreOffice Basic automatically inserts a SUB called "Main". This default name has nothing to do with the order or the starting point of a LibreOffice Basic project. You can also safely rename this SUB.


Ikon Catatan

Some restrictions apply for the names of your public variables, subs, and functions. You must not use the same name as one of the modules of the same library.


Procedures (SUBS) and functions (FUNCTIONS) help you maintaining a structured overview by separating a program into logical pieces.

Satu keuntungan dari prosedur dan fungsi adalah ketika Anda selesai mengembangkan sebuah kode program yang mengandung komponen-komponen tugas di dalamnya, maka kode-kode ini bisa Anda pakai pada proyek yang lain.

Melewatkan Variabel ke Prosedur (SUB) dan Fungsi (FUNCTION)

Variables can be passed to both procedures and functions. The SUB or FUNCTION must be declared to expect parameters:

Sub SubName(Parameter1 As Type, Parameter2 As Type,...)

Kode program

End Sub

SUB dipanggil dengan sintaksis berikut:

SubName(Value1, Value2,...)

The parameters passed to a SUB must fit to those specified in the SUB declaration.

The same process applies to FUNCTIONS. In addition, functions always return a function result. The result of a function is defined by assigning the return value to the function name:

Function FunctionName(Parameter1 As Type, Parameter2 As Type,...) As Type

Kode program

FunctionName=Result

End Function

FUNCTION dipanggil dengan sintaksis berikut:

Variabel=NamaFungsi(Parameter1, Parameter2,...)

Ikon Tip

You can also use the fully qualified name to call a procedure or function:
Library.Module.Macro()
For example, to call the Autotext macro from the Gimmicks library, use the following command:
Gimmicks.AutoText.Main()


Passing Variables by Value or Reference

Parameters can be passed to a SUB or a FUNCTION either by reference or by value. Unless otherwise specified, a parameter is always passed by reference. That means that a SUB or a FUNCTION gets the parameter and can read and modify its value.

If you want to pass a parameter by value insert the key word "ByVal" in front of the parameter when you call a SUB or FUNCTION, for example:

Result = Function(ByVal Parameter)

In this case, the original content of the parameter will not be modified by the FUNCTION since it only gets the value and not the parameter itself.

Scope of Variables

A variable defined within a SUB or FUNCTION, only remains valid until the procedure is exited. This is known as a "local" variable. In many cases, you need a variable to be valid in all procedures, in every module of all libraries, or after a SUB or FUNCTION is exited.

Mendeklarasikan Varibel di Luar SUB atau FUNCTION

GLOBAL VarName As TYPENAME

The variable is valid as long as the LibreOffice session lasts.

PUBLIC VarName As TYPENAME

Variabelnya sah untuk semua modul.

PUBLIC VarName As TYPENAME

Variabelnya hanya sah untuk modul ini.

PUBLIC VarName As TYPENAME

Variabelnya hanya sah untuk modul ini.

Contoh untuk variabel privat

Enforce private variables to be private across modules by setting CompatibilityMode(true).

' ***** Module1 *****

Private myText As String

Sub initMyText

    myText = "Hello"

    print "in module1 : ", myText

End Sub

 

' ***** Module2 *****

'Option Explicit

Sub demoBug

    CompatibilityMode( true )

    initMyText

    ' Sekarang menghasilkan string kosong

    ' (atau mencapai kesalahan/error pada Option Explicit)

    print "Now in module2 : ", myText

End Sub

Menyimpan Isi Variabel Usai Keluar dari SUB atau FUNCTION

STATIC VarName As TYPENAME

The variable retains its value until the next time the FUNCTION or SUB is entered. The declaration must exist inside a SUB or a FUNCTION.

Specifying the Return Value Type of a FUNCTION

As with variables, include a type-declaration character after the function name, or the type indicated by "As" and the corresponding key word at the end of the parameter list to define the type of the function's return value, for example:

Function WordCount(WordText As String) As Integer