-optionexplicit

Causes the compiler to report errors if variables are not declared before they are used.

-optionexplicit[+ | -]  

+ | -
Optional. Specify -optionexplicit+ to require explicit declaration of variables. The -optionexplicit+ option is the default and is the same as -optionexplicit. The -optionexplicit- option enables implicit declaration of variables.

If the source code file contains an Option Explicit statement, the statement overrides the -optionexplicit command-line compiler setting.

1. Have a project selected in Solution Explorer. On the Project menu, click Properties.

2. Click the Compile tab.

3. Modify the value in the Option Explicit box.

The following code compiles when -optionexplicit- is used.

Module Module1
    Sub Main()
        i = 99
        System.Console.WriteLine(i)
    End Sub
End Module

• Visual Basic Command-Line Compiler
• -optioncompare
• -optionstrict
• -optioninfer
• Sample Compilation Command Lines
• Option Explicit Statement
• Visual Basic Defaults, Projects, Options Dialog Box