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  3. c# Casting v As operator

c# Casting v As operator

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  • R Richard A Dalton

    If an illegal cast is an exceptional (woah, that should never happen) situation, then (a) If there's a possibility that through normal use the cast might be invalid (e.g. Plug-in tpye code), then (b), followed by an If to check for Null. -Richard

    Hit any user to continue.

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    NormDroid
    wrote on last edited by
    #28

    Richard A. Dalton wrote:

    Plug-in tpye code

    That's the only situation I could eve think off, normally you should be aware if the cast would fail or not.

    www.software-kinetics.co.uk Wear a hard hat it's under construction

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    • N NormDroid

      I used raw COM when the COM specs where first released, wow you needed a ton of code to do a small task. But it did give me background on the workings of COM.

      www.software-kinetics.co.uk Wear a hard hat it's under construction

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      Aamir Butt
      wrote on last edited by
      #29

      Norm .net wrote:

      wow you needed a ton of code to do a small task

      Check the section "Master Programmer" in this link. :)[^]

      A year spent in artificial intelligence is enough to make one believe in God

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      • N NormDroid

        For those using c#, what do you prefer? A.

        SomeObject obj = (SomeObject) e;

        or B.

        SomeObject obj = e as SomeObject;

        www.software-kinetics.co.uk Wear a hard hat it's under construction

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        Dave Parker
        wrote on last edited by
        #30

        It depends on what you're trying to do, the two things are different. If you're certain e is a SomeObject then I'd cast it. If it may or may not be I'd usually use the as keyword, in which case obj would be null if it isn't a SomeObject as opposed to throwing an exception.

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        • N Nagy Vilmos

          There seems to be alot of white space in your sig.


          Panic, Chaos, Destruction. My work here is done. Drink. Get drunk. Fall over - P O'H OK, I will win to day or my name isn't Ethel Crudacre! - DD Ethel Crudacre I cannot live by bread alone. Bacon and ketchup are needed as well. - Trollslayer Have a bit more patience with newbies. Of course some of them act dumb - they're often *students*, for heaven's sake - Terry Pratchett

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          W Balboos GHB
          wrote on last edited by
          #31

          Possibly a font-problem on your end? It looks roughly like: W**.'.** Balboos - the three punctuation-like characters being the HTML character code: & there4; (space put in after & so it doesn't render)

          "The difference between genius and stupidity is that genius has its limits." - Albert Einstein

          "As far as we know, our computer has never had an undetected error." - Weisert

          "If you are searching for perfection in others, then you seek disappointment. If you are seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010

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          • A Aamir Butt

            Norm .net wrote:

            wow you needed a ton of code to do a small task

            Check the section "Master Programmer" in this link. :)[^]

            A year spent in artificial intelligence is enough to make one believe in God

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            NormDroid
            wrote on last edited by
            #32

            Oh that brings back memories, and forgetting idl files :)

            www.software-kinetics.co.uk Wear a hard hat it's under construction

            1 Reply Last reply
            0
            • W W Balboos GHB

              Possibly a font-problem on your end? It looks roughly like: W**.'.** Balboos - the three punctuation-like characters being the HTML character code: & there4; (space put in after & so it doesn't render)

              "The difference between genius and stupidity is that genius has its limits." - Albert Einstein

              "As far as we know, our computer has never had an undetected error." - Weisert

              "If you are searching for perfection in others, then you seek disappointment. If you are seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010

              N Offline
              N Offline
              Nagy Vilmos
              wrote on last edited by
              #33

              Not your name, your sig:

              W∴ Balboos wrote:

              Possibly a font-problem on your end?
               
              It looks roughly like: W**.'.** Balboos - the three punctuation-like characters being the HTML character code: & there4; (space put in after & so it doesn't render)

              "The difference between genius and stupidity is that genius has its limits." - Albert Einstein

              "As far as we know, our computer has never had an undetected error." - Weisert

              "If you are searching for perfection in others, then you seek disappointment. If you are seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010

              There's a lot of white space...


              Panic, Chaos, Destruction. My work here is done. Drink. Get drunk. Fall over - P O'H OK, I will win to day or my name isn't Ethel Crudacre! - DD Ethel Crudacre I cannot live by bread alone. Bacon and ketchup are needed as well. - Trollslayer Have a bit more patience with newbies. Of course some of them act dumb - they're often *students*, for heaven's sake - Terry Pratchett

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              • N NormDroid

                It's a debate, not a question.

                www.software-kinetics.co.uk Wear a hard hat it's under construction

                N Offline
                N Offline
                Nagy Vilmos
                wrote on last edited by
                #34

                To be or not to be.? That is a question. :-D


                Panic, Chaos, Destruction. My work here is done. Drink. Get drunk. Fall over - P O'H OK, I will win to day or my name isn't Ethel Crudacre! - DD Ethel Crudacre I cannot live by bread alone. Bacon and ketchup are needed as well. - Trollslayer Have a bit more patience with newbies. Of course some of them act dumb - they're often *students*, for heaven's sake - Terry Pratchett

                N 1 Reply Last reply
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                • N Nagy Vilmos

                  To be or not to be.? That is a question. :-D


                  Panic, Chaos, Destruction. My work here is done. Drink. Get drunk. Fall over - P O'H OK, I will win to day or my name isn't Ethel Crudacre! - DD Ethel Crudacre I cannot live by bread alone. Bacon and ketchup are needed as well. - Trollslayer Have a bit more patience with newbies. Of course some of them act dumb - they're often *students*, for heaven's sake - Terry Pratchett

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                  NormDroid
                  wrote on last edited by
                  #35

                  Nope wrong, you've omitted the ? mark. ;)

                  www.software-kinetics.co.uk Wear a hard hat it's under construction

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                  • N NormDroid

                    Nope wrong, you've omitted the ? mark. ;)

                    www.software-kinetics.co.uk Wear a hard hat it's under construction

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                    Nagy Vilmos
                    wrote on last edited by
                    #36

                    Did I?


                    Panic, Chaos, Destruction. My work here is done. Drink. Get drunk. Fall over - P O'H OK, I will win to day or my name isn't Ethel Crudacre! - DD Ethel Crudacre I cannot live by bread alone. Bacon and ketchup are needed as well. - Trollslayer Have a bit more patience with newbies. Of course some of them act dumb - they're often *students*, for heaven's sake - Terry Pratchett

                    N 1 Reply Last reply
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                    • N Nagy Vilmos

                      Did I?


                      Panic, Chaos, Destruction. My work here is done. Drink. Get drunk. Fall over - P O'H OK, I will win to day or my name isn't Ethel Crudacre! - DD Ethel Crudacre I cannot live by bread alone. Bacon and ketchup are needed as well. - Trollslayer Have a bit more patience with newbies. Of course some of them act dumb - they're often *students*, for heaven's sake - Terry Pratchett

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                      N Offline
                      NormDroid
                      wrote on last edited by
                      #37

                      The hand is quicker than the I eye.

                      www.software-kinetics.co.uk Wear a hard hat it's under construction

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                      • N NormDroid

                        a. Throw back from C++ programming.

                        www.software-kinetics.co.uk Wear a hard hat it's under construction

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                        Quirkafleeg
                        wrote on last edited by
                        #38

                        Wrong - a is C-style casting, not C++

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                        • Q Quirkafleeg

                          Wrong - a is C-style casting, not C++

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                          NormDroid
                          wrote on last edited by
                          #39

                          Splitting hairs :)

                          www.software-kinetics.co.uk Wear a hard hat it's under construction

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                          • N Nagy Vilmos

                            Norm .net wrote:

                            Good point.

                            Holy cr_p! I'm going to the pub, we'll see what comes out after lunch! :laugh:


                            Panic, Chaos, Destruction. My work here is done. Drink. Get drunk. Fall over - P O'H OK, I will win to day or my name isn't Ethel Crudacre! - DD Ethel Crudacre I cannot live by bread alone. Bacon and ketchup are needed as well. - Trollslayer Have a bit more patience with newbies. Of course some of them act dumb - they're often *students*, for heaven's sake - Terry Pratchett

                            N Offline
                            N Offline
                            NormDroid
                            wrote on last edited by
                            #40

                            :beer:

                            www.software-kinetics.co.uk Wear a hard hat it's under construction

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                            • H hairy_hats

                              Which is exactly why this is more of a programming question than a "lifestyle choice" question.

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                              NormDroid
                              wrote on last edited by
                              #41

                              I'd say more of a debate, but as we all know rules of the lounge, I'd say just go along with it and chill :)

                              www.software-kinetics.co.uk Wear a hard hat it's under construction

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                              • N NormDroid

                                True, but you should know beforehand if the casting is correct.

                                www.software-kinetics.co.uk Wear a hard hat it's under construction

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                                Fabio Franco
                                wrote on last edited by
                                #42

                                If you do know something is not gonna be null, the cast is more efficient.

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                                • F Fabio Franco

                                  If you do know something is not gonna be null, the cast is more efficient.

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                                  NormDroid
                                  wrote on last edited by
                                  #43

                                  To add... and the cast is a qualified cast.

                                  www.software-kinetics.co.uk Wear a hard hat it's under construction

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                                  • N NormDroid

                                    For those using c#, what do you prefer? A.

                                    SomeObject obj = (SomeObject) e;

                                    or B.

                                    SomeObject obj = e as SomeObject;

                                    www.software-kinetics.co.uk Wear a hard hat it's under construction

                                    S Offline
                                    S Offline
                                    Sahir Shah
                                    wrote on last edited by
                                    #44

                                    The second one sounds like some kind of hominid comrade Norm.

                                    Und wenn du lange in einen abgrund blickst, blickt der Abgrund auch in dich hinein.

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                                    • S Sahir Shah

                                      The second one sounds like some kind of hominid comrade Norm.

                                      Und wenn du lange in einen abgrund blickst, blickt der Abgrund auch in dich hinein.

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                                      NormDroid
                                      wrote on last edited by
                                      #45

                                      Don't fancy seeing your code if you think b. looks like a great ape :rolleyes:

                                      www.software-kinetics.co.uk Wear a hard hat it's under construction

                                      S 1 Reply Last reply
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                                      • N NormDroid

                                        For those using c#, what do you prefer? A.

                                        SomeObject obj = (SomeObject) e;

                                        or B.

                                        SomeObject obj = e as SomeObject;

                                        www.software-kinetics.co.uk Wear a hard hat it's under construction

                                        OriginalGriffO Offline
                                        OriginalGriffO Offline
                                        OriginalGriff
                                        wrote on last edited by
                                        #46

                                        B. I don't like to rely on exceptions for normal processing (they are slow and clumsy for that), so you have to check for null.

                                        SomeObject obj = e as SomeObject;
                                        if (obj != null)
                                        {
                                        ...
                                        }

                                        While

                                        if (e != null && e is SomeObject)
                                        {
                                        SomeObject obj = (SomeObject) e;
                                        ...
                                        }

                                        looks ugly. Plus, if you are going to use obj as a SomeObject instance, then the former is quicker since there is only one check on the type of e

                                        Real men don't use instructions. They are only the manufacturers opinion on how to put the thing together. Manfred R. Bihy: "Looks as if OP is learning resistant."

                                        "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
                                        "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

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                                        • R Ravi Bhavnani

                                          It depends.  (A) will throw if the cast fails while (B) will evaluate to null if the cast fails.  I use both depending on how I intend to handle the casting failure. /ravi

                                          My new year resolution: 2048 x 1536 Home | Articles | My .NET bits | Freeware ravib(at)ravib(dot)com

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                                          jim lahey
                                          wrote on last edited by
                                          #47

                                          I'm with Ravi on this one.I use both, the decision if which one to use is purely based upon what I need to happen should it go wrong

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