Constants

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Constants are values which may be used but not changed by the program.

Defining Constants

In Apache OpenOffice Basic, use the keyword Const to declare a constant.

ConstA=10
ConstB=A+5
ConstHi="Hello World"
Documentation caution.png Do not specify the constant type in the declaration : it will be silently ignored.

This code shows that you do not get the type that you specify.

ConstalphaAsLong=1
ConstbetaAsSingle=3.1
ConstgammaAsBoolean=True
ConstdeltaAsCurrency=123456.05
ConstphiAsLong=32768
MsgBox(TypeName(alpha))' displays : Integer
MsgBox(TypeName(beta))' displays : Double
MsgBox(TypeName(gamma))' displays : Integer
MsgBox(TypeName(delta))' displays : Double
MsgBox(TypeName(phi))' displays : Double

As Basic makes automatic type conversions, there is usually no problems using a constant in an expression.

If you want to specify the type of a data, use a typed variable, not a constant.

Scope of Constants

Constants have the same scope as variables (see Scope and Life Span of Variables), but the syntax is slightly different. A Const definition in the module header is available to the code in that module. To make the definition available to other modules, add the Public keyword.

PublicConstone=1

Predefined Constants

Apache OpenOffice Basic predefines several constants. Among the most useful are:

  • True and False, for Boolean assignment statements
  • PI as a type Double numeric value
DimbHitasBoolean
bHit=True
DimdAreaasDouble,dRadiusasDouble
' ... (assign a value to dRadius)
dArea=PI*dRadius*dRadius


Content on this page is licensed under the Public Documentation License (PDL).



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