OpenOffice.org Macros Explained - LibreOffice-NA.US

precede Option Explicit because they are not runnable. Although it would be even better if this became a
compile-time error, OOo Basic does not resolve all variables and routines until run time.
Listing 6. Use Option Explicit before the first runnable line in a macro.
REM ***** BASIC *****
Option Explicit
TIP
Use “Option Explicit” at the top of every macro that you write; it will save you a lot of time searching for
errors in your code. When I am asked to debug a macro, the first thing I do is add “Option Explicit” at the
top of each module.
You can declare a variable with or without a type. A variable without an explicit type becomes a Variant,
which is able to take on any type. This means that you can use a Variant to hold a numeric value and then, in
the next line of code, overwrite the number with text. Table 4 shows the variable types supported by OOo
Basic, the value that each type of variable contains immediately after declaration (“initial value”), and the
number of bytes that each type uses. In OOo Basic, a variable's type can be declared by appending a special
character to the end of the name when it is declared. The Post column in Table 4 contains the supported
characters that can be post-fixed to a variable's name when the variable is declared.
Table 4. Supported variable types and their initial values.
Type Post Initial Bytes Convert Description
Boolean False 1 CBool True or False
Currency @ 0.0000 8 CCur Currency with 4 decimal places
Date 00:00:00 8 CDate Dates and times
Double # 0.0 8 CDbl Decimal numbers in the range of
+/-1.79769313486232 x 10E308
Integer % 0 2 CInt Integer from -32,768 through 32,767
Long & 0 4 CLng Integer from -2147483648 through
2147483647
Object Null varies Object
Single ! 0.0 4 CSng Decimal numbers in the range of
+/-3.402823 x 10E38
String $ "" varies CStr Text with up to 65536 characters
Variant Empty varies CVar May contain any data type
Although OOo Basic supports a Byte variable type, you can’t directly declare and use one. The function
CByte, as discussed later, returns a Byte value that may be assigned to a variable of type Variant. With OOo
version 2.0, you can declare a variable of type Byte, but the variable is assumed to be an externally defined
object of type Byte rather than an internally defined Byte variable.
Use the DIM keyword to explicitly declare a variable before use (see Table 5). You can declare multiple
variables on a single line, and you can give each variable a type when it is declared. Variables with no
declared type default to type Variant.
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