Description
For a List and a Combo with Style 'Simple', this property specifies the position of the data in the list box as a positive integer value. If Index has the value "n", it means that the "nth" item in Items is displayed on the top line in the list box. The value of Index is dependent upon the value of ⎕IO. Note that Index for a Combo or List cannot be set using ⎕WC. The value of Index in a Combo with a drop-down list box (Style 'Drop' or 'DropEdit') is always equal to ⎕IO.
For a Grid, Index is a 2-element vector that specifies the row and column number of the cell that is currently in the top left corner of the Grid.
For a TreeView, Index is a positive integer value that specifies which item appears at the top of the TreeView window.
For a FileBox, the Index property determines which of the Filters is initially selected.
For a CoolBand, the Index property specifies the position of the CoolBand within its parent CoolBar, relative to the other CoolBands in the CoolBar.
The value of Index is dependent on ⎕IO, and its default value is equal to ⎕IO.