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Build a string for arithmetic operationHi all Can I build a string for arithmetic operation. (VB NET 2005) e.g. I want to build an arithmetic operation from within the program as mVariable="A1+A2+A3" (where A1=1, A2=5, A3=10) (A1,A2 & A3 are variables declared as integers) mTotal=mVariable (mTotal should return 16) If there is any other way to do what I want I would appreciate if someone can guide me. Thank you. Mike TI
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On Nov 13, 8:31 pm, "Mike TI" <tanv***@creativepk.com> wrote: I'm confused - why not just do this?> Nov 13, 2007 > > Hi all > > Can I build a string for arithmetic operation. (VB NET 2005) > > e.g. > > I want to build an arithmetic operation from within the program as > > mVariable="A1+A2+A3" (where A1=1, A2=5, A3=10) (A1,A2 & A3 are variables > declared as integers) > > mTotal=mVariable (mTotal should return 16) > > If there is any other way to do what I want I would appreciate if someone > can guide me. > > Thank you. > Mike TI Dim mVariable As Integer = A1 + A2 + A3 Thanks, Seth Rowe Think he really wants to do something like ...
mTotal = Eval(MVariable) .... and I would be interested in something like that. Have an VB6 project I will need to convert some day that uses an old 'Awk' control for this type of thing. It fires an event when it needs the value of a 'token' it does not recognize, allowing you to suibstitue the value for the token. I think it may be possible using Regx, but I have not explored it yet. -- Show quoteHide quoteTerry "rowe_newsgroups" wrote: > On Nov 13, 8:31 pm, "Mike TI" <tanv***@creativepk.com> wrote: > > Nov 13, 2007 > > > > Hi all > > > > Can I build a string for arithmetic operation. (VB NET 2005) > > > > e.g. > > > > I want to build an arithmetic operation from within the program as > > > > mVariable="A1+A2+A3" (where A1=1, A2=5, A3=10) (A1,A2 & A3 are variables > > declared as integers) > > > > mTotal=mVariable (mTotal should return 16) > > > > If there is any other way to do what I want I would appreciate if someone > > can guide me. > > > > Thank you. > > Mike TI > > I'm confused - why not just do this? > > Dim mVariable As Integer = A1 + A2 + A3 > > Thanks, > > Seth Rowe > > On Nov 13, 9:39 am, Terry <Ter...@nospam.nospam> wrote:
Show quoteHide quote > Think he really wants to do something like ... Ahh, for Eval you might take a look at the following thread:> > mTotal = Eval(MVariable) > > ... and I would be interested in something like that. Have an VB6 project I > will need to convert some day that uses an old 'Awk' control for this type of > thing. It fires an event when it needs the value of a 'token' it does not > recognize, allowing you to suibstitue the value for the token. I think it > may be possible using Regx, but I have not explored it yet. > > -- > Terry > > "rowe_newsgroups" wrote: > > On Nov 13, 8:31 pm, "Mike TI" <tanv***@creativepk.com> wrote: > > > Nov 13, 2007 > > > > Hi all > > > > Can I build a string for arithmetic operation. (VB NET 2005) > > > > e.g. > > > > I want to build an arithmetic operation from within the program as > > > > mVariable="A1+A2+A3" (where A1=1, A2=5, A3=10) (A1,A2 & A3 are variables > > > declared as integers) > > > > mTotal=mVariable (mTotal should return 16) > > > > If there is any other way to do what I want I would appreciate if someone > > > can guide me. > > > > Thank you. > > > Mike TI > > > I'm confused - why not just do this? > > > Dim mVariable As Integer = A1 + A2 + A3 > > > Thanks, > > > Seth Rowe http://groups.google.com/group/microsoft.public.dotnet.languages.vb/browse_thread/thread/1dcc3718f955806a/08ed83cd46ba1808?hl=en&lnk=gst&q=eval#08ed83cd46ba1808 Thanks, Seth Rowe Seth,
I think that Tom and know I find that a very good thread. :-) CorOn Nov 13, 1:38 pm, "Cor Ligthert[MVP]" <notmyfirstn***@planet.nl> lolwrote: > Seth, > > I think that Tom and know I find that a very good thread. > > :-) > > Cor I love it when you two do all the work for me! Posting links is *so* much easier than retyping a solution. :-) Thanks,Seth Rowe Nov 14, 2007
Hi I have checked links, still apparently they do not answer my question. I want to build an expression from within the program and then store it in a variable like mVariable="A1+A2+A3" Now I want to put the result of the above into another variable like mTotal=Eval(mVariable) The applications should return the value as if I had entered mTotal=A1+A2+A3 Thank you. Mike TI Show quoteHide quote "Mike TI" <tanv***@creativepk.com> wrote in message news:OB62MmfJIHA.588@TK2MSFTNGP05.phx.gbl... > Nov 13, 2007 > > Hi all > > Can I build a string for arithmetic operation. (VB NET 2005) > > e.g. > > I want to build an arithmetic operation from within the program as > > mVariable="A1+A2+A3" (where A1=1, A2=5, A3=10) (A1,A2 & A3 are > variables declared as integers) > > mTotal=mVariable (mTotal should return 16) > > If there is any other way to do what I want I would appreciate if someone > can guide me. > > Thank you. > Mike TI > > > I have checked links, still apparently they do not answer my question. And why not? Could you tell us what exactly didn't work?Also you still never answered why you are needing this and why you can't simply do: mTotal = A1 + A2 + A3 And avoid all the messy Eval stuff. Thanks, Seth Rowe Nov 14, 2007
Hellow Seth I am converting a Payroll application that I did in MS Visual Foxpro. In this application how an Allowance or Deduction is defined is flexible. Just to give you a simple example: For one company the basis can be as below: Allowances: ALL01 1,000 ALL02 100 ALL03 500 ALL04 45% of ALL01+ALL02+ALL03 ALL05 10% of ALL01+ALL03 if no Leave Without Pay For another company the basis can be as below: Allowances: ALL01 1,000 ALL02 100 ALL03 500 ALL04 45% of ALL01+ALL02 ALL05 10% of ALL01+ALL02+ALL03 if no Leave Without Pay Now I want to build the calculation for ALL04 & ALL05 from within the program. There are some other alternates. However I was wondering if I could do the way I was doing in VFP. Also I was wondering if I could load a form getting the name stored in a variable. Thanks Mike TI Show quoteHide quote "rowe_newsgroups" <rowe_em***@yahoo.com> wrote in message news:1195039765.991732.40720@57g2000hsv.googlegroups.com... >> I have checked links, still apparently they do not answer my question. > > And why not? Could you tell us what exactly didn't work? > > Also you still never answered why you are needing this and why you > can't simply do: > > mTotal = A1 + A2 + A3 > > And avoid all the messy Eval stuff. > > Thanks, > > Seth Rowe >
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"Mike TI" <tanv***@creativepk.com> schrieb You must write a parser and interpret the input on you own.> Nov 14, 2007 > > Hellow Seth > > I am converting a Payroll application that I did in MS Visual > Foxpro. In this application how an Allowance or Deduction is defined > is flexible. Just to give you a simple example: > > For one company the basis can be as below: > > Allowances: > > ALL01 1,000 > ALL02 100 > ALL03 500 > ALL04 45% of ALL01+ALL02+ALL03 > ALL05 10% of ALL01+ALL03 if no > Leave Without Pay > > For another company the basis can be as below: > > Allowances: > > ALL01 1,000 > ALL02 100 > ALL03 500 > ALL04 45% of ALL01+ALL02 > ALL05 10% of ALL01+ALL02+ALL03 if > no Leave Without Pay > > Now I want to build the calculation for ALL04 & ALL05 from within > the program. There are some other alternates. However I was > wondering if I could do the way I was doing in VFP. > Also I was wondering if I could load a form getting the name stored Whenever I read this, I wonder how a class name, that is only relevant to> in a variable. the developer, which means it gets out of interest after the source code has been compiled, how this class names makes it's way through to run-time as the content of a variable. The only exception is whenever the class name is also stored externally. In this case, I recommend writing a Select Case statment based upon the string and create the corresponding instance. This enables the compiler to check the class name at compile time and it is more straight forward than using Reflection (see System.Activator.Creatinstance). Armin
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"Mike TI" <tanv***@creativepk.com> schrieb "A1+A2+A3" is an expression. An expression has a syntax. If you need VB.net> Nov 14, 2007 > > Hi > > I have checked links, still apparently they do not answer my > question. > > I want to build an expression from within the program and then store > it in a variable like > > mVariable="A1+A2+A3" > > Now I want to put the result of the above into another variable like > > mTotal=Eval(mVariable) > > The applications should return the value as if I had entered > > mTotal=A1+A2+A3 > > Thank you. syntax, you need a VB.Net compiler. The compiler compiles to IL code, and the JIT compiler will compile it to native code when executed. An executable statement in VB.Net must be part of a procedure/method. A method is part of a class. The class must belong to a project. You don't have a project. So, in order to execute a line you must 1. create a project 2. add a class 3. add a procedure 4. add an executable line 5. compiler the project 6. run the executable Alternatively, have a look at the System.Reflection.Emit namespace. There you will also have to create an assembly, a class, a method and executable code. What you want to do is not possible because you don't give the line an environment to live in. Armin Apoligies if this has been covered. My nesreader lists this as the first
post in this thread (clearly not the case) I have used a Library called eval3 found @ http://www.codeproject.com/dotnet/eval3.asp with great success. If memory serves you get to new up an evaluator of sorts and then add Name/Value pairs to it in order to define the values of variables which can be evaluated Pseudocode ( again just the basic Idea, Not actual syntax as I can't remember it right now) Dim Ev As New Evaluator Ev.Add("A1", 10) Ev.Add("A2", 12) Ev.Add("A3", 14) Ev.Add("A4" 16) Dim Answer as Integer = Ev.Evaluate("A1+A2+A3+A4") ' Answer will now = 52 Is this of any use? BTW Eval3 is way more powerful than this. It allows you to define your own functions in .Net Code and Access then directly from the String which Gets Evaluated. -- Rory 
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