KeyCompareMode

Returns or sets the comparison mode used when matching string keys in a Collection object. Read/write.

Syntax:

  • object.KeyCompareMode
  • object.KeyCompareMode = compare
object
required An object expression that evaluates to a Collection object.
compare
A VbCompareMethod value specifying the comparison mode used by Add, Item, Remove and Exists when looking up keys.

The compare argument settings are:

Constant Value Description
vbBinaryCompare 0 Performs a case-sensitive binary comparison.
vbTextCompare 1 Performs a case-insensitive textual comparison.

Note

KeyCompareMode is a twinBASIC extension; the classic VBA Collection object always uses case-insensitive comparison and does not expose this property.

The default comparison mode is vbTextCompare, whatever the module’s Option Compare setting, so a new Collection matches keys as VBA’s does.

The mode can be changed only while the collection holds no item added with a key. Items added without a key do not prevent the change, and neither do keyed items that have since been removed or cleared. Setting the mode the collection already has is allowed at any time.

Common Errors

Error When
5 (&H5), Invalid procedure call or argument compare is not vbBinaryCompare or vbTextCompare after rounding
5 (&H5), Can’t change KeyCompareMode once keyed items have been added to the collection the mode is changed while the collection holds an item added with a key; the mode stays as it was
94 (&H5E), Invalid use of Null compare is Null

Example 

Dim col As New Collection

' The default mode is text: "A" and "a" are the same key.
col.Add "first", Key:="A"
' col.Add "second", Key:="a"   ' Would raise error 457: the key is already in use.

Dim col2 As New Collection
col2.KeyCompareMode = vbBinaryCompare   ' Before any item is added with a key.
col2.Add "first", Key:="A"
col2.Add "second", Key:="a"   ' A different key from "A", so it succeeds.

See Also