Lazy declaration of variables.
The
qb and
fblite FreeBASIC language dialects allow variable names to be used without declaring them first. This is called implicit or lazy declaration since the actual declaration is inferred from how the name is first used.
Variable Type
When a variable is implicitly declared, its type depends on one of two things: the most recent default implicit type directive, if any, or the variable type suffix symbol used, if any.
Default type
In the
qb dialect, implicitly declared variables default to
Single type, while in the
fblite dialect they default to
Integer type.
Default implicit type directives
Variable type suffix symbols
Variable names suffixed with one of a certain set of symbols will be implicitly declared of a certain type. These symbols are:
'%' for
Integer,
'&' for
Long,
'!' for
Single,
'#' for
Double and
'$' for
String. These symbols override previous "
DEFxxx" directives, if any.
Implicit Array Declaration
Currently, FreeBASIC does not support implicit declaration of arrays.
Debugging
For full debugging support, all variables must be explicitly declared and suffixes should not be used. The use of
Option Explicit is recommended to turn of support for implicit declarations, so that mistyped variable names are caught at compile time by the compiler.
See also