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  4. how can i know whether an optional parameter is passed or not?

how can i know whether an optional parameter is passed or not?

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  • E Expert Coming

    For a pretty damn perfect explaination MSDN[^]

    The best way to accelerate a Macintosh is at 9.8m/sec² - Marcus Dolengo

    D Offline
    D Offline
    Dragonfly_Lee
    wrote on last edited by
    #9

    Hi, dude, optional keyword is for VB.net, not C#.

    :) I Love KongFu~

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    • A abhiram_nayan

      basically, i can achieve it by having an overloaded funciton, but, it is just a small issue that i do not want to have another overload of the function. I am having a funciton with 2 parameters and now i want to introduce a 3rd optional parameter. I just want to know whether the caller of the function passed the 3rd argument or not?

      D Offline
      D Offline
      Dragonfly_Lee
      wrote on last edited by
      #10

      abhiram_nayan wrote:

      now i want to introduce a 3rd optional parameter.

      Would you please paste the code? I really do not know how to do this...

      :) I Love KongFu~

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      • A abhiram_nayan

        thanks.

        D Offline
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        DaveyM69
        wrote on last edited by
        #11

        Can't do that until C# 4.0 which hasn't been released yet.

        Dave
        BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
        Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

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        • D dan sh

          There is nothing like optional parameter in C#.

          Time is the best teacher; unfortunately it kills all of its students. जय हिंद

          M Offline
          M Offline
          Mirko1980
          wrote on last edited by
          #12

          Not until C# 4, at least. (Oook, DaveyM69 posted the same thing at the same time... ;P)

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          • D DaveyM69

            Can't do that until C# 4.0 which hasn't been released yet.

            Dave
            BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
            Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

            A Offline
            A Offline
            abhiram_nayan
            wrote on last edited by
            #13

            this means, i should go with an overloaded function, that's it?!

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            • A abhiram_nayan

              this means, i should go with an overloaded function, that's it?!

              M Offline
              M Offline
              Mirko1980
              wrote on last edited by
              #14

              If there is not anything that stops you from adding another overload (such as conflicting signature with another overload), yes. Alternatively, you can mimic an optional parameter by addin a parameter that accepts null values, and using a default value in the method body if null has been received.

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              • D DaveyM69

                Can't do that until C# 4.0 which hasn't been released yet.

                Dave
                BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
                Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

                A Offline
                A Offline
                ABitSmart
                wrote on last edited by
                #15

                In reference to C# 4.0, I was just curious, would it be possible to know if an optional parameter was passed or no ? If we did not pass the value, it would take the default value which is defined. But how will the body know if the optional parameter was passed or no ?

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                • A ABitSmart

                  In reference to C# 4.0, I was just curious, would it be possible to know if an optional parameter was passed or no ? If we did not pass the value, it would take the default value which is defined. But how will the body know if the optional parameter was passed or no ?

                  M Offline
                  M Offline
                  Mirko1980
                  wrote on last edited by
                  #16

                  Well, it will not know. It will use the default value without worring if it was passed by the caller or automatically used. The whole point of optional parameters is to make that logic transparent to the method implementation.

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                  • M Mirko1980

                    Well, it will not know. It will use the default value without worring if it was passed by the caller or automatically used. The whole point of optional parameters is to make that logic transparent to the method implementation.

                    A Offline
                    A Offline
                    ABitSmart
                    wrote on last edited by
                    #17

                    Well, I understand that. Looking at the OP's question and the given reference to C# 4.0 Optional parameters, made me curious.

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                    • A abhiram_nayan

                      dude! Default parameter specifiers are not permitted in C#!!! http://blogs.msdn.com/csharpfaq/archive/2004/03/07/85556.aspx[^]

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                      Lost User
                      wrote on last edited by
                      #18

                      I don't want to be nit-picky, but C# 4.0 actually does support default parameters :)

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                      • L Lost User

                        I don't want to be nit-picky, but C# 4.0 actually does support default parameters :)

                        N Offline
                        N Offline
                        naresh_prakash
                        wrote on last edited by
                        #19

                        In Microsoft published Framework 2.0, few examples exists when you need to passing optional parameters... i haven't book with me now but i know it is possible. I'll show you examples later bec i already used it.... Thanks Naresh Prakash

                        L 1 Reply Last reply
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                        • N naresh_prakash

                          In Microsoft published Framework 2.0, few examples exists when you need to passing optional parameters... i haven't book with me now but i know it is possible. I'll show you examples later bec i already used it.... Thanks Naresh Prakash

                          L Offline
                          L Offline
                          Lost User
                          wrote on last edited by
                          #20

                          I also heard they were already supported in the .NET 2.0 CLR, but for some reason the features were not exposed to the C# language.

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