ComArray.Item

Returns an item by index or by key from an Array, List or Dictionary collection.

This works on (keytype):

  • Array (int)
  • Array List (int)
  • IList (int)
  • ICollection (any type)
  • HashSet (any type)
  • IDictionary (key type) (or int for index)

You can specify either an integer for list types or any type for collections. int keys are 0 based.

For dictionaries int values retrieve the item at the specified indexed location, unless the Dictionary key type is int.

If the key type is int (or a FoxPro number) the int key is treated as a key value, rather than an index. For all other key types, the key is treated as an index.

public object Item(object indexOrKey)

Return Value

matching item or null

Parameters

indexOrKey
int 0 based key for lists or any value for collections/dicionaries

Exceptions

**System.ArgumentException**
Invalid index or key type

Remarks

Dictionaries can use an int value to return a value out of the collection by its index **if the key type is not of System.Int. This is a special case and allows you to iterate a dictionary which otherwise would not be possible.

Example

*** Access generic list through indirect access through Proxy and get ComArray
loList = loBridge.InvokeMethod(loNet,"GetGenericList")
? loBridge.ToString(loList)   && System.Collections.Generic.List...
? loList.Count && 2

*** Grab an item by index
loCust =  loList.Item(0)
? loCust.Company

*** Iterate the list
FOR lnX = 0 TO loList.Count -1
   loItem = lolist.Item(lnX)
   ? loItem.Company
ENDFOR

*** Retrieve a generic dictionary 
loList = loBridge.InvokeMethod(loNet,"GetDictionary")
? loList.Count  &&  2

*** Return Item by Key
loCust =  loList.Item("Item1")   && Retrieve item by Key
? loCust.Company

*** This works as long as the key type is not int
loCust =  loList.Item(0)   && Retrieve item by Index
? loCust.Company

*** This allows iterating a dictionary
FOR lnX = 0 TO loList.Count -1
   loItem = lolist.Item(lnX)
   ? loItem.Company
ENDFOR

See also:

Class ComArray
© West Wind Technologies, 1996-2024 • Updated: 04/17/24
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