Option Definition

Syntax

Option Base [0|1]
-or-
Option Compare [Binary | Text]
-or-
Option Explicit
-or-
Option UsesAmbiguousError [On | Off]

Group

Declaration

Description

Option Base: Set the default base index for array declarations. Affects Dim, Static, Private, Public, and ReDim. Does not affect Array, ParamArray, or arrays declare in a Type. Option Base 0 is the default.

Option Compare: Set the default comparison mode for <, <=, =, >, >=, <>, Like and StrComp.

• Option Compare Binary - Compares string text using binary data (default).
• Option Compare Text - Compares string text using the collation rules.

Option Explicit - Requires all variables to be declared prior to use. Variables are declared using Dim, Private, Public, Static, or as a parameter of Sub, Function, or Property blocks.

Option UsesAmbiguousError On - When an unqualified symbol not defined in the current macro/module and it is defined in more than one '#Uses module, an Ambiguous name error occurs. (This is the default.) Disabling this error allows the first matching symbol in a '#Uses module to be matched. The '#Uses providing the first matching symbol is implementation dependent and not predictable.

---

Option Base 1
Option Explicit
 
Sub Main
    Dim A
        Dim C(2) ' same as Dim C(1 To 2)
        Dim D(0 To 2)
    A = 1
    B = 2 ' B has not been declared
End Sub