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The Daily Newbie - Using the Choose() Function

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Submitted on: 1/16/2015 7:22:00 PM
By: Matthew Roberts (from psc cd)  
Level: Beginner
User Rating: By 6 Users
Compatibility: VB 3.0, VB 4.0 (16-bit), VB 4.0 (32-bit), VB 5.0, VB 6.0, VB Script, ASP (Active Server Pages) , VBA MS Access, VBA MS Excel
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     04/28/2001 - Describes the usage of the Choose() function; A really neat but seldom used command in VB.

 
				



Daily Newbie - 04/28/2001


The Daily Newbie

“To Start Things Off Right”

Fourth Edition April 28, 2001 Free

About this feature:

The initial plan for the Daily Newbie was to cover each function VB has to offer in alphabetical order. I have now modified this plan slightly to skip over some of the more advanced (or tedious) commands that I don't think the Newbie would benefit from. Thanks again all who have written in support of this effort. It makes a difference.

Today's command is not widely known for some reason, but is faily useful. I have been guilty of writing functions that do the exact same thing several times. I think you will like this one.

Today’s Keyword: Choose()

Name Derived From:

Choose (of course) – “(1) : to make a selection" - Webster's online dictionary.

Used for Making a choice between several possible options.

VB Help Description: Selects and returns a value from a list ofarguments.

Plain English: Returns the option associated with the value passed it (I will just have to show you!)

Syntax: Choose(index, Choice1, Choice2, etc...)

Usage: strDecision = Choose(intChoice , "Just do it" , "Don't do it" , "It's your life" )

Copy & Paste Code:



Today's code snippet will prompt for a month number and return a string that corresponds to it.

 Dim Choice
 Dim strMonth As String
Do
Choice = Val(InputBox("Enter a Number (1-12):"))
If Choice + 0 = 0 Then Exit Do
strMonth = Choose(Choice, "Jan", "Feb", "Mar", "Apr", _
"May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec")
MsgBox strMonth
Loop

Notes:

I really like the Choose function. It comes in handy for with evaluating which option button was clicked, or anything else that returns an index number. Unfortunatly, like the Array() command covered a couple of articles ago, the Choose() function requires a seperate hard coded value for each possible choice. This isn't neccesarily a bad thing, but I am allergic to hard coding, so it just rubs me wrong. I guess the chances of the order of the months changing is pretty slim...

Things to watch out for:

  • Although the Choose() Statement only returns a single value, it still evaluates each one. In effect, it acts like a compact series of If...Then statements. This can result in the sometimes baffling behavior of displaying one message box with the correct value and many empty ones. For this reason, the results of a Choose() statement should be returned to a variable before displaying it in a message box.

  • If the Index value passed in is null, an error will result. Therefore, if you are using a variant as your Index, you should add zero to it to initialize it as a number. This will make the default value zero, not null.

    Tomorrow's Keyword: Chr()


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