Returntype of Methods

Returntype of Methods

• Handschuh

  Returning Object works, you'd have to cast the Object back to the type of the variable you're assigning. Something like:
  int ival = (int)myObject.getText(s, len, type);
  
  A much cleaner way that doesn't require casting is to provide overloads of the getText method, one for each type you're handling. For example:
  class MyObject
  {
  public void getText(String s, out int value) { value = 1; }
  public void getText(string s, out double value) { value = 2; }
  }
  
  int ival;
  double dval;
  
  switch(str) {
  case "N":
  myObject.getText(s, out ival);
  // Do something with ival...
  break;
  case "D":
  myObject.getText(s, out dval);
  break;
  ...
  }
  
  
  
  

• Lawrence Parker

  hai philip,
  
  thanks for ur reply. will check it out....
  
  regards
  swingme
  

• Sculptor

  hallo nobugz,
  
  thanks for ur reply. with objects i have tried out and it works.. but as u told may be overloading may be a much better solution.. will try it.
  
  regards
  swingme
  
  
  

• rapidexposure

  Nope, nobugz is referring to Reflection to retreive the returntype of a method you specified earlier, or one you get from an assembly. You would like to write a method without knowing the type you are returning, right
  
  Maybe defining an interface which you can return will do the trick: define an interface for the basics, and let your objects imlpement it. That way you can return any object as long as it implements your interface.
  
  An example (BTW: of course it is not best practice to define the interface and the implementing class and a calling class in the same file, but this is just a sample  ):
  

  public class InterfaceTest
  {
    /// <summary>
    /// Interface definition, containing a name
    /// </summary>
  
    public interface ITest
    {
      string Name
      {
        get;
        set;
      }
    }
  
    /// <summary>
    /// Class definition, implementing ITest and adding an Age property
    /// </summary>
    public class TestA : ITest
    {
      private string name;
      private int age;
  
      public string Name
      {
        get
        {
          return name;
        }
        set
        {
          name = value;
        }
      }
  
      public int Age
      {
        get
        {
          return age;
        }
        set
        {
          age = value;
        }
      }
    }
  
    /// <summary>
    /// Method with a returntype of 'ITest'. This can be an instance of TestA, r any other class implementing the ITest interface
    /// </summary>
    /// <returns>An object implementing ITest</returns>
    public ITest GetObject()
    {
      return new TestA();
    }
  }

  
  
  

• Jessica Alba

  Hallo nobugz!
  
  Thanks for ur reply. That means i can define a method like
  
  private <reflection> Test()
  {
  .................
  .................
  
  return <reflection....>
  }
  
  
  ist it
  
  regards
  swingme
  
  

• Franco Finstad

  If "type" is an actual type, you can use generics for this as well:

  public T getText<T>(string s, int len)
  {
  //return whatever you wish
  return default(T);
  }

  switch(str){
  case "N":
  len = str.length;
  myObject.getText<DateTime>(s, len);
  .....
  
  Not sure if this is what you mean, though it requres that the calling code knows the return type in advance (although you'll need that to cast to if you're going to use it).

  
  

• JD Prasad

  I think you need to clarify what you want to do. Specifically, to you want to DETERMINE the return type of a method, or do you want to CHANGE it
  
  
  

• WinFXGuy

  Thank you for you replies. What i want is that i dont want to fix the return type of the method at time of compilation. depending on certain conditions i would like to change it between int , string etc..
  
  regards
  swingme
  
  
  
  

• boxelder

  Any possible return type always converts to an Object. As long as the clients can figure it out, make the return type Object. It's the .NET version of a Variant...
  
  
  
  

• Joe Duanel

  Thank u nobugz for ur reply. its ofcourse a solution...but i am eager to know, what features of c# will i make it unusable as james suggests.
  
  regards
  swingme
  
  

• GWeston

  Yes, System.Reflection.
  
  
  

• jerry_tseng

  thank u very much rick for ur reply. i will try it out.
  
  regards
  swingme
  
  
  
  

• NeilG

  what i need is as follows...
  
  switch(str) {
  case "N":
  len = str.length;
  myObject.getText( s, len,type);
  break;
  case "D":
  len = str.length;
  myObject.getText(s, len,type);
  break;
  .........................
  ........................
  
  Ist it possible for GetText to return an object depending on "type" GetText may return date , string...etc
  
  regards
  swingme
  
  
  
  

• sagittarian

  Returning an Object as nobugz suggests is a workable solution, although it involves "turning off" many features that C# provides for you. IF you could provided a more specific example of what you want to do, we could provide a more appropriate response.
  
  
  
  
• Returntype of Methods