Possible Duplicate:
what’s an option strict and explicit?
Is it about case sensitivity? Complete noob here.
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40answers:
2
+1
A:
According to MSDN:
Used at file level to force explicit declaration of all variables in that file.
Otherwise you can just use a variable without having to declare it first.
They even included an example:
Option Explicit On ' Force explicit variable declaration.
Dim MyVar As Integer ' Declare variable.
MyInt = 10 ' Undeclared variable generates error.
MyVar = 10 ' Declared variable does not generate error.
Justin Ethier
2010-05-18 19:46:44
like using dim?
phearn
2010-05-18 19:47:17
it lets you "declare" variables just by using it for the first time. In the sample above, MyInt becomes a variable just by using it without a Dim statement. ALWAYS use Option Explicit if you can, it will save you many headaches. Dim is an explicit variable declaration, MyInt above is an implicit one.
Jeremy
2010-05-18 19:49:45
A:
When option explicit is off visual basic allows you to implicitly declare a variable by assigning a value to it. This is a really bad idea as misspelling a variable name would silently create a new variable causing a very hard to find bug.
Option Explicit Off
Imports System
Public Class ImplicitVariable
Public Shared Sub Main()
a = 33
Console.WriteLine("a has value '{0}' and type {1}", a, a.GetType())
End Sub
End Class
Andy
2010-05-18 19:56:37