Creates a new javafx.beans.binding.StringBinding that contains the element of an javafx.collections.ObservableList at the specified position. The StringBinding will hold "" if the index is outside of the ObservableList.

Parameters:

op		the ObservableList
index		the position in the List, converted to int

Returns:  the new StringBinding

Exceptions:

NullPointerException

if the ObservableList or index is null

Since:  JavaFX 8.0