Option Explicit Statement

From Visual Basic Scripting

Microsoft® Visual Basic® Scripting Edition Option Explicit Statement  Language Reference 
Version 1 


Description

Forces explicit declaration of all variables in a script.

Syntax

Option Explicit

Remarks

If used, the Option Explicit statement must appear in a script before any other statements.

When you use the Option Explicit statement, you must explicitly declare all variables using the Dim, Private, Public, or ReDim statements. If you attempt to use an undeclared variable name, an error occurs.


Tip  Use Option Explicit to avoid incorrectly typing the name of an existing variable or to avoid confusion in code where the scope of the variable is not clear.

The following example illustrates use of the Option Explicit statement:

Option Explicit    ' Force explicit variable declaration.
Dim MyVar          ' Declare variable.
MyInt = 10         ' Undeclared variable generates error.
MyVar = 10         ' Declared variable does not generate error.