char: Letter prefix that specifies default data type for variables.
char-char: Letter range prefixes that specify default data type for variables.
Example:
' Prefix definitions for variable types:
DefBool b
DefCur c,l-m
DefDate t
DefDbl f
DefErr e
DefInt i-k,N
DefLng x-z, D
DefObj U, o-R
DefSng w,a
DefStr s
DefVar V,g
DefErr e
Sub ExampleDefErr
eErr=Error REM eErr 是隱式的錯誤變數
End Sub