What does Option Explicit mean and do?

Cosmos75 · Apr 12th, 2002, 11:26 AM

Can anyone help explain what does Option Explicit means and what does it do in a macro? (kinda redundant, I know, since the topic is self-explanatory)

Mudface · Apr 12th, 2002, 11:30 AM

From the VBA help files, explains it quite neatly really and should always be your first port of call: -

Used at module level to force explicit declaration of all variables in that module.

Syntax

Option Explicit

Remarks

If used, the Option Explicit statement must appear in a module before any procedures.

When Option Explicit appears in a module, you must explicitly declare all variables using the Dim, Private, Public, ReDim, or Static statements. If you attempt to use an undeclared variable name, an error occurs at compile time.

If you don't use the Option Explicit statement, all undeclared variables are of Variant type unless the default type is otherwise specified with a Deftype statement.

Note 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.

Cosmos75 · Apr 12th, 2002, 11:34 AM

Sorry about that. But my computer at work doesn't have the VBA help files installed. And I am not sure if the IT people would want me to install it.

Is there an online source where I can look all of this up?

Joe Was · Apr 12th, 2002, 11:41 AM

It forces variable definitions. This helps when you use variables to hold and insert or exchange data or controls with in code. This form allows for a clear scope of use when variable usage is complicated or could become unclear. Its use also helps keep frequently used variables from being miss-typed. Helps keep variables from being assigned a variant type if not defined with a Def statement. The down side is it can only be used in a true module.

The skinny on it is: It forces explicit variable declaration. Hope this helps. JSW

Mudface · Apr 12th, 2002, 11:42 AM

Oh, no, I wasn't having a go at you

. It was meant just as a tip as the help files are very useful. I don't see why IT wouldn't let you have them, they should be there after a standard Excel/ Office install anyway.

Mark O'Brien · Apr 12th, 2002, 11:43 AM

It would probably be easier to go and ask your IT people to install it or install it yourself if your system does that "install on first use" thingy.

If they say "no" demand a reason. If the reason is insufficient give them so many lefts that they'll be begging for a right.

Verbal abuse doesn't seem to have much effect on IT people (ours have built up a tolerance to it), stick to the violence.

HTH

Cosmos75 · Apr 12th, 2002, 11:58 AM

MudFace,
Don''t worry about it. I just was apologizing for not being able to find things on my own and bothering gooe people like you and the others who have responded to this with a question, I should be able to answer on my own.

Anyway,
Here's a link I found that might be useful.

http://msdn.microsoft.com/library/de...hanges2000.asp

Apr 12th, 2002, 11:43 AM	#6
Mark O'Brien MrExcel MVP Join Date: Feb 2002 Location: Columbus, OH, USA Posts: 3,519	It would probably be easier to go and ask your IT people to install it or install it yourself if your system does that "install on first use" thingy. If they say "no" demand a reason. If the reason is insufficient give them so many lefts that they'll be begging for a right. Verbal abuse doesn't seem to have much effect on IT people (ours have built up a tolerance to it), stick to the violence. HTH __________________ Mark O'Brien Columbus Ohio Celtic Supporters Club

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Apr 12th, 2002, 11:26 AM	#1
Cosmos75 Board Regular Join Date: Feb 2002 Location: Tulsa, OK Posts: 354	Can anyone help explain what does Option Explicit means and what does it do in a macro? (kinda redundant, I know, since the topic is self-explanatory)

Apr 12th, 2002, 11:30 AM	#2
Mudface MrExcel MVP Join Date: Feb 2002 Location: Sunny, spring-like Hull Posts: 3,339	From the VBA help files, explains it quite neatly really and should always be your first port of call: - Used at module level to force explicit declaration of all variables in that module. Syntax Option Explicit Remarks If used, the Option Explicit statement must appear in a module before any procedures. When Option Explicit appears in a module, you must explicitly declare all variables using the Dim, Private, Public, ReDim, or Static statements. If you attempt to use an undeclared variable name, an error occurs at compile time. If you don't use the Option Explicit statement, all undeclared variables are of Variant type unless the default type is otherwise specified with a Deftype statement. Note 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.

Apr 12th, 2002, 11:34 AM	#3
Cosmos75 Board Regular Join Date: Feb 2002 Location: Tulsa, OK Posts: 354	Sorry about that. But my computer at work doesn't have the VBA help files installed. And I am not sure if the IT people would want me to install it. Is there an online source where I can look all of this up?

Apr 12th, 2002, 11:41 AM	#4
Joe Was MrExcel MVP Join Date: Feb 2002 Location: Central Florida, USA Posts: 7,541	It forces variable definitions. This helps when you use variables to hold and insert or exchange data or controls with in code. This form allows for a clear scope of use when variable usage is complicated or could become unclear. Its use also helps keep frequently used variables from being miss-typed. Helps keep variables from being assigned a variant type if not defined with a Def statement. The down side is it can only be used in a true module. The skinny on it is: It forces explicit variable declaration. Hope this helps. JSW

Apr 12th, 2002, 11:42 AM	#5
Mudface MrExcel MVP Join Date: Feb 2002 Location: Sunny, spring-like Hull Posts: 3,339	Oh, no, I wasn't having a go at you . It was meant just as a tip as the help files are very useful. I don't see why IT wouldn't let you have them, they should be there after a standard Excel/ Office install anyway.

Apr 12th, 2002, 11:58 AM	#7
Cosmos75 Board Regular Join Date: Feb 2002 Location: Tulsa, OK Posts: 354	MudFace, Don''t worry about it. I just was apologizing for not being able to find things on my own and bothering gooe people like you and the others who have responded to this with a question, I should be able to answer on my own. Anyway, Here's a link I found that might be useful. http://msdn.microsoft.com/library/de...hanges2000.asp