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  • Your email address will not be published.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

  • The first phase of API management was about realizing the business value of APIs. This next wave of API management enables the hyper-connected enterprise to drive and scale their businesses as API models become more complex and sophisticated. Today, real world product launches begin with an API program and strategy in mind. This API-first approach to development will only continue to increase, driven by an increasingly interconnected web of devices, organizations, and people. To support this rapid growth, …

  • 10 Rules that Make or Break Enterprise App Development Projects In today's app-driven world, application development is a top priority. Even so, 68% of enterprise application delivery projects fail. Designing and building applications that pay for themselves and adapt to future needs is incredibly difficult. Executing one successful project is lucky, but making it a repeatable process and strategic advantage? That's where the money is. With help from our most experienced project leads and software engineers, …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds