Improved Mid$ Statement

During the course of my work, I often write complex string parsing and manipulation algorithms. The last thing I want, is to have to add more checks to make sure that my string positions are not negative.

I can avoid the hassle by using the following function when I need to use Mid. It wraps around native Visual Basic functionality and handles this common error case.

public Function FlexiMid(From as string, Start as Long, _
       optional Length as Long = -1) as string

    If Start < 1 then Start = 1
    FlexiMid = IIf(Length = -1, mid$(From, Start), _
               mid$(From, Start, Length))

End Function

Once you've pasted this function into your program (I recommend a module, so that you can access it from anywhere), you can use it just as you would Mid. In fact, once I wrote this, I ran a search and replace on my project to start using it.


  • MID$

    Posted by Legacy on 08/19/2002 12:00am

    Originally posted by: Arjen Stins

    public Function FlexiMid(From as string, Start as Long, optional Length as Long = -1) as string
    If Start < 1 then Start = 1
    If Length < 1 Then
    FlexiMid = mid$(From, Start)
    FlexiMid = mid$(From, Start, Length)
    End if
    End Function

    Don't use iif with functions in true and false part.
    They are both evaluated. In the original FlexiMid, all mid$ are processed, but only 1 result is returned.

    In this Flexmid only the mid$ that's returned is processed.

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • On-demand Event Event Date: September 23, 2015 The cloud is not just about a runtime platform for your projects – now, you can do your development in the cloud, too. Check out this webcast to learn how the cloud improves your development experience and team collaboration. Join Dana Singleterry, Principal Product Manager for Oracle Dev Tools, as he discusses how to simplify every aspect of the development lifecycle, including requirements gathering, version management, code reviews, build automation, and …

  • Lenovo recommends Windows 8 Pro. "I dropped my laptop getting out of the taxi." This probably sounds familiar to most IT professionals. If your employees are traveling, you know their devices are in for a rough go. Whether it's a trip to the conference room or a convention out of town, any time equipment leaves a user's desk it is at risk of being put into harm's way. Stay connected at all times, whether at the office or on the go, with agile, durable, and flexible devices like the Lenovo® …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date