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  4. Object initializers. [modified]

Object initializers. [modified]

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  • R Roger Alsing 0

    What do you mean with this?:

    John Simmons / outlaw programmer wrote:

    Putting the constructor body here is, IMHO, bad programming technique

    It's not like you are moving the ctor out from the class and into the initializer. the initializer is the initializer, configuring stuff that are not default values. eg: Person you = new Person() {FirstName = "John",LastName="Simmons"}; Ofcourse you could write your own constructor that takes those as in params. But there are cases where a class has alot of properties and you are not likely to provide a constructor with every possible set of in param combination for those. Or did I completely misinterpret what you said?

    My Blog

    realJSOPR Online
    realJSOPR Online
    realJSOP
    wrote on last edited by
    #14

    This falls neatly under the category of "Just because you *can* do it, doesn't mean you *should* do it". Why is that better than writing the appropriate constructor and using new Person("John", "Simmons");? Further, an appropriately designed class initializes all of its properties when it's instantiated. This new feature of .Net appears to propagate lazy programmers.

    "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
    -----
    "...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

    CPalliniC R P J 4 Replies Last reply
    0
    • realJSOPR realJSOP

      This falls neatly under the category of "Just because you *can* do it, doesn't mean you *should* do it". Why is that better than writing the appropriate constructor and using new Person("John", "Simmons");? Further, an appropriately designed class initializes all of its properties when it's instantiated. This new feature of .Net appears to propagate lazy programmers.

      "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
      -----
      "...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

      CPalliniC Offline
      CPalliniC Offline
      CPallini
      wrote on last edited by
      #15

      John Simmons / outlaw programmer wrote:

      This new feature of .Net appears to propagate lazy programmers.

      All the .NET thing goes in such a direction... :-D

      If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
      This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke
      [My articles]

      In testa che avete, signor di Ceprano?

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      • realJSOPR realJSOP

        This falls neatly under the category of "Just because you *can* do it, doesn't mean you *should* do it". Why is that better than writing the appropriate constructor and using new Person("John", "Simmons");? Further, an appropriately designed class initializes all of its properties when it's instantiated. This new feature of .Net appears to propagate lazy programmers.

        "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
        -----
        "...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

        R Offline
        R Offline
        Roger Alsing 0
        wrote on last edited by
        #16

        John Simmons / outlaw programmer wrote:

        Why is that better than writing the appropriate constructor

        As I said in my first post. Lets assume that your class contains 20 properties, all of those recieve default values in the default ctor. And the user only wants to init custom values in 5 of them.. (Think winforms control or such, eg a grid) Should you create a constructor for each possible combination of properties that the user _might_ want to set? No way..

        My Blog

        D 1 Reply Last reply
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        • R Roger Alsing 0

          John Simmons / outlaw programmer wrote:

          Why is that better than writing the appropriate constructor

          As I said in my first post. Lets assume that your class contains 20 properties, all of those recieve default values in the default ctor. And the user only wants to init custom values in 5 of them.. (Think winforms control or such, eg a grid) Should you create a constructor for each possible combination of properties that the user _might_ want to set? No way..

          My Blog

          D Offline
          D Offline
          Dan Neely
          wrote on last edited by
          #17

          Not to mention if they're all the same type you can't create a ctors for all of them. That said, this is just a return of optional parameters. Personally I'd prefer a syntax of FooBar myFooBar = new FooBar(1,2,,,5,,,8,,,,,,15,,,,19,20); and a ctor that looked like FooBar(optional int param1, optional int param2, optional int param3,.... ) {...}

          Today's lesson is brought to you by the word "niggardly". Remember kids, don't attribute to racism what can be explained by Scandinavian language roots. -- Robert Royall

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          • realJSOPR realJSOP

            This falls neatly under the category of "Just because you *can* do it, doesn't mean you *should* do it". Why is that better than writing the appropriate constructor and using new Person("John", "Simmons");? Further, an appropriately designed class initializes all of its properties when it's instantiated. This new feature of .Net appears to propagate lazy programmers.

            "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
            -----
            "...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

            P Offline
            P Offline
            PIEBALDconsult
            wrote on last edited by
            #18

            Ten! Or we should be able to use something like the syntax that Attributes use.

            1 Reply Last reply
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            • P PIEBALDconsult

              Ah, more new "features" to avoid. I wish they'd add the features the I want.

              R Offline
              R Offline
              RugbyLeague
              wrote on last edited by
              #19

              I am still holding out for them to add a DoAllMyWork class ;P

              D 1 Reply Last reply
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              • R RugbyLeague

                I am still holding out for them to add a DoAllMyWork class ;P

                D Offline
                D Offline
                Dan Neely
                wrote on last edited by
                #20

                You can make one by inheriting HireRentACoder and implementing CheapOutsourcing().

                Today's lesson is brought to you by the word "niggardly". Remember kids, don't attribute to racism what can be explained by Scandinavian language roots. -- Robert Royall

                R 1 Reply Last reply
                0
                • D Dan Neely

                  You can make one by inheriting HireRentACoder and implementing CheapOutsourcing().

                  Today's lesson is brought to you by the word "niggardly". Remember kids, don't attribute to racism what can be explained by Scandinavian language roots. -- Robert Royall

                  R Offline
                  R Offline
                  RugbyLeague
                  wrote on last edited by
                  #21

                  Do you implement CheapOutsourcing() in VB thus: Me = Nothing

                  D 1 Reply Last reply
                  0
                  • R RugbyLeague

                    Do you implement CheapOutsourcing() in VB thus: Me = Nothing

                    D Offline
                    D Offline
                    Dan Neely
                    wrote on last edited by
                    #22

                    Note quite. Me.SelfWorth = Nothing

                    Today's lesson is brought to you by the word "niggardly". Remember kids, don't attribute to racism what can be explained by Scandinavian language roots. -- Robert Royall

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                    • G Giorgi Dalakishvili

                      Pete O'Hanlon wrote:

                      You can't initialize objects like this.

                      That's correct but the above code compiles. But foo.Name is not initialized. That's why it is a subtle bug ;)

                      Giorgi Dalakishvili #region signature my articles My blog[^] #endregion

                      L Offline
                      L Offline
                      led mike
                      wrote on last edited by
                      #23

                      Giorgi Dalakishvili wrote:

                      That's why it is a subtle bug

                      Sure. It's a bug that is created by a developer that does not understand that Properties are NOT the same thing as member variables.

                      led mike

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                      • realJSOPR realJSOP

                        I didn't know you could do this (citing the correct way to do it):

                        Foo foo = new Foo() { Description="Blah", Name="name"};

                        Putting the constructor body here is, IMHO, bad programming technique.

                        "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
                        -----
                        "...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

                        J Offline
                        J Offline
                        Jorgen Sigvardsson
                        wrote on last edited by
                        #24

                        It translates to

                        Foo foo = new Foo();
                        foo.Description = "Blah";
                        foo.Name = "name";

                        How's that bad programming technique?

                        -- Kein Mitleid Für Die Mehrheit

                        1 Reply Last reply
                        0
                        • G Giorgi Dalakishvili

                          class Foo
                          {
                          public string Description { get; set; }
                          public String Name { get; set; }
                          }

                          public partial class Form1 : Form
                          {
                          public Form1()
                          {
                          InitializeComponent();
                          }

                          private void InitFoo()
                          {
                          Foo foo = new Foo() { Description = Name = "name" };
                          }
                          }

                          After running InitFoo method foo.Name is not initialized. Can you spot the bug? You can see answer at my blog post: Object Initializers and Possible Bugs[^]

                          Giorgi Dalakishvili #region signature my articles My blog[^] #endregion

                          modified on Friday, September 19, 2008 2:19 AM

                          R Offline
                          R Offline
                          Redwan Albougha
                          wrote on last edited by
                          #25

                          Really subtle !! I changed the properties order as Mirko1980 said, Visual Studio is telling me 'Description' does not exist in the current context.:confused: I tend to think that if you do a one step initialization, you can put just one member of your object at the most left side of the assignment, one and just one; why don't ask me :wtf:

                          Best wishes, Redwan Al-Bougha

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                          0
                          • realJSOPR realJSOP

                            This falls neatly under the category of "Just because you *can* do it, doesn't mean you *should* do it". Why is that better than writing the appropriate constructor and using new Person("John", "Simmons");? Further, an appropriately designed class initializes all of its properties when it's instantiated. This new feature of .Net appears to propagate lazy programmers.

                            "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
                            -----
                            "...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

                            J Offline
                            J Offline
                            Jamie Nordmeyer
                            wrote on last edited by
                            #26

                            I look at it as one of those "if you don't like it, don't use it" things. Frankly, I think it'll make code cleaner and more concise. Instead of 10 different constructors for various combination's of things you MIGHT pass in, this syntax allows you to explicitly initialize the object how you want it. The only real change I've seen in C# so far since its creation that truly scares me is the 'dynamic' keyword in C# 4. I like the idea of it when you're trying to work with interop (like access the Excel object library, for instance), but like the 'unsafe' keyword, you should have to tell the compiler explicitly that you mean it. And THEN, it should only be usable on interop types. You should also never be able to return a dynamic type from methods or properties. In other words:

                            // Allowed, if a DYNAMIC compiler flag is enabled.
                            dynamic range = Excel.Application.CurrentWorkbook.CurrentSheet.Range("A1:B3");

                            // NEVER allowed.
                            dynamic x = 3;

                            Kyosa Jamie Nordmeyer - Taekwondo Yi (2nd) Dan Portland, Oregon, USA

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