Getting an array's index from custom valued indexed array

Question

SortedList<string, int> list = new SortedList<string, int>;
list.Add("abc", 2);
list.Add("def", 3);

string index = list.GetIndex(2) ???????
Console.WriteLine(index);

I'm really confused. How can I get an array's index by using the index's value??

Output should be

abc

Solutions:

Use the IndexOfValue method that SortedList exposed, with combination of the Linq extension method ElementAt(int index), so:

string index = list.ElementAt(list.IndexOfValue(value)).Key;//output will be abc

---o---

This also works

string index = list.Keys.ElementAt<string>(list.IndexOfValue(2));

I'm just as confused as you are. What array? I don't see any array. — BoltClock
– BoltClock, Commented Aug 24, 2011 at 13:29
If the 2 and 3 are just index references, why not just use a list of strings, or a dictionary of int, string? — Johnie Karr
– Johnie Karr, Commented Aug 24, 2011 at 13:32
Actually I've got an SortedList with ToolStripMenuItem as index and Form as value. — haxxoromer
– haxxoromer, Commented Aug 24, 2011 at 13:35

Jalal Said · Accepted Answer · 2011-08-24 13:46:00Z

1

Use the IndexOfValue method that SortedList exposed, with combination of the Linq extension method ElementAt(int index), so:

string index = list.ElementAt(list.IndexOfValue(value)).Key;//output will be abc

edited Aug 24, 2011 at 13:46

answered Aug 24, 2011 at 13:39

Jalal Said

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1 Comment

haxxoromer Over a year ago

Thank you ! This also works (I've just found it) string index = list.Keys.ElementAt<string>(list.IndexOfValue(2));

vinayvasyani · Accepted Answer · 2011-08-24 13:36:41Z

1

MSDN Documentation about SortedList.GetByIndex method:

using System;
using System.Collections;
public class SamplesSortedList  {

   public static void Main()  {

      // Creates and initializes a new SortedList.
      SortedList mySL = new SortedList();
      mySL.Add( 1.3, "fox" );
      mySL.Add( 1.4, "jumped" );
      mySL.Add( 1.5, "over" );
      mySL.Add( 1.2, "brown" );
      mySL.Add( 1.1, "quick" );
      mySL.Add( 1.0, "The" );
      mySL.Add( 1.6, "the" );
      mySL.Add( 1.8, "dog" );
      mySL.Add( 1.7, "lazy" );

      // Gets the key and the value based on the index.
      int myIndex=3;
      Console.WriteLine( "The key   at index {0} is {1}.", myIndex, mySL.GetKey( myIndex ) );
      Console.WriteLine( "The value at index {0} is {1}.", myIndex, mySL.GetByIndex( myIndex ) );

      // Gets the list of keys and the list of values.
      IList myKeyList = mySL.GetKeyList();
      IList myValueList = mySL.GetValueList();

      // Prints the keys in the first column and the values in the second column.
      Console.WriteLine( "\t-KEY-\t-VALUE-" );
      for ( int i = 0; i < mySL.Count; i++ )
         Console.WriteLine( "\t{0}\t{1}", myKeyList[i], myValueList[i] );
   }
}
/* 
This code produces the following output.

The key   at index 3 is 1.3.
The value at index 3 is fox.
    -KEY-    -VALUE-
    1    The
    1.1    quick
    1.2    brown
    1.3    fox
    1.4    jumped
    1.5    over
    1.6    the
    1.7    lazy
    1.8    dog
*/

answered Aug 24, 2011 at 13:36

vinayvasyani

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3 Comments

haxxoromer Over a year ago

I think this is not supported in NET 4.0

vinayvasyani Over a year ago

Refer this link. It clearly states that it is supported in all versions of .Net.

vinayvasyani Over a year ago

msdn.microsoft.com/en-us/library/…

Devin Burke · Accepted Answer · 2011-08-24 13:52:12Z

1

Based on your statement that the output should be abc, I think you really want the text, not the index. To get the text of an item based on its value, simply do the following:

SortedList<string, int> list = new SortedList<string, int>();
list.Add("abc", 2);
list.Add("def", 3);
string text = list.ElementAt(listz.IndexOfValue(2)).Key
Console.WriteLine(text);

edited Aug 24, 2011 at 13:52

answered Aug 24, 2011 at 13:35

Devin Burke

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3 Comments

haxxoromer Over a year ago

There's no Property like Item in SortedList -_-

haxxoromer Over a year ago

invalid arguments. list is based on string not integer.

Devin Burke Over a year ago

Sorry, you are absolutely right. It's correct now! I tested it and it returns abc.

Peladao · Accepted Answer · 2011-08-24 13:31:40Z

0

Use the SortedList.Values property to get an ICollection object containing the values in the SortedList object.

answered Aug 24, 2011 at 13:31

Peladao

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Comments

James Johnson · Accepted Answer · 2011-08-24 13:36:04Z

0

Give this a shot:

SortedList<string, int> list = new SortedList<string, object>();
list.Add("One", 1);
list.Add("Two", 2);                               

int value = (int)list.ElementAt(1).Value;

Or...

int value = list.IndexOfKey("One");

answered Aug 24, 2011 at 13:36

James Johnson

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