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Thread: Evaluate an expression in vb.net

  1. #1

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    Evaluate an expression in vb.net

    Hi ALL, my program uses formulas and prompt users for variables values e.g.
    Code:
    Height= "(x*2)-5+y/2"
    then i do:
    Code:
     height.replace("x","5.5").replace("y","9")
    now how to evaluate height into a decimal ?

  2. #2
    Super Moderator jmcilhinney's Avatar
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    Re: Evaluate an expression in vb.net

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  3. #3
    Angel of Code Niya's Avatar
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    Re: Evaluate an expression in vb.net

    Doesn't the DataTable provide a method that can evaluate expressions ?
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  4. #4
    Super Moderator jmcilhinney's Avatar
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    Re: Evaluate an expression in vb.net

    Quote Originally Posted by Niya View Post
    Doesn't the DataTable provide a method that can evaluate expressions ?
    Now that you mention it, I do recall someone else suggesting the DataTable.Compute method for this purpose some other time, which is something that I'd never considered. It feels like a bit of a hack but it certainly does the job, within certain limitations.
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  5. #5
    Angel of Code Niya's Avatar
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    Re: Evaluate an expression in vb.net

    Yea...it is a bit of a hack I guess. The first one from your search has some really nice features like being able to reference properties on live objects to use as part of its evaluations.
    Treeview with NodeAdded/NodesRemoved events | BlinkLabel control | Calculate Permutations | Object Enums | ComboBox with centered items | .Net Internals article(not mine) | Wizard Control | Understanding Multi-Threading | Simple file compression | Demon Arena

    Copy/move files using Windows Shell | I'm not wanted

    C++ programmers will dismiss you as a cretinous simpleton for your inability to keep track of pointers chained 6 levels deep and Java programmers will pillory you for buying into the evils of Microsoft. Meanwhile C# programmers will get paid just a little bit more than you for writing exactly the same code and VB6 programmers will continue to whitter on about "footprints". - FunkyDexter

    There's just no reason to use garbage like InputBox. - jmcilhinney

    The threads I start are Niya and Olaf free zones. No arguing about the benefits of VB6 over .NET here please. Happiness must reign. - yereverluvinuncleber

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