sorting arraylist of structures

[dudleys]

Hi,

I have an ArrayList of structures and I want to sort the array on different members of the structure so that I can give a rank each element of the array.

So I thought I would sort it for each member in turn add add a rank member to the structure for each member i want to sort

Confusing I bet.

How else would you do this? I want to step through a database fill an array then sort by differen members and then rank each member in the array so that I can create a table with the member values and there rank next to it

Thanks for any help given
dudley

 

[sweth]

using sorted arraylist we can store rank and value and sort them by rank. Refer the following code
Dim slsStates As New SortedList

slsStates.Add("CA", "California")
slsStates.Add("AZ", "Arizona")
slsStates.Add("NV", "Nevada")

' slsStates order:
'
' Keys | Values
' ---------------
' AZ | Arizona
' CA | California
' NV | Nevada

 

[dudleys]

Don't know what you mean?

 

[RTomes]

I think you may need to use sweths' approache above.
Write a class the put each member of your structure into it's own sortedList. Since your structure members are custom I don't think there is going to anything off the shelf that will do it without some extra writing.

 

[dudleys]

It seems there is no other way then to put each in its own sorted list.

Ok thanks

 

[chiph]

If you add an implementation of IComparer to your data structure (hopefully it's a class, not a struct). You can then call the .Sort method on the ArrayList.

Class States : IComparer
{
   public string StateAbbr;
   public string StateFull;

   // Default constructor
   public States()
   {
   }

   public States(string abbr, string full)
   {
      StateAbbr = abbr;
      StateFull = full;
   }

   // Implementation of IComparer
   // sorts by the state abbreviation
   public int Compare(object x, object y)
   {
      if (x == null)
         return -1;
      else
         States stateX = x as States;

      if (y == null)
         return 1;
      else
         States stateY = y as States;
      
      return stateX.StateAbbr.CompareTo(stateY.StateAbbr);
   }
}

to use it:

ArrayList a = new ArrayList();
a.Add(new States("CA", "California"));
a.Add(new States("AZ", "Arizona"));
a.Add(new States("NV", "Nevada"));

a.Sort();

Chip H.


____________________________________________________________________
If you want to get the best response to a question, please read FAQ222-2244 first