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.



Comments

  • 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$(From, Start)
    Else
    FlexiMid = mid$(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.

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  • Your email address will not be published.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

Top White Papers and Webcasts

  • Organizations are increasingly gravitating toward mobile-first application development as they assess the need to revamp their application portfolios to support touch computing and mobility. Consumerization has brought higher expectations for application usability along with the mobile devices themselves. Enterprises are increasingly shifting their new application acquisitions and development efforts toward mobile platforms. With this backdrop, it is natural to expect application platform vendors to invest in …

  • By now you've likely heard of Agile development and building products in small incremental pieces, so you can get real feedback along the way. In fact, you may even be considering using Agile on your next project. But where do you start? Agile can take a lot of forms, such as Scrum or Kanban. Each form has advantages and disadvantages, but both will help your team get the right feedback they need to build great products. Read this white paper to find out which one is right for you.

Most Popular Programming Stories

More for Developers

RSS Feeds

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