On the API of JList there is a link to "How To Use Lists" in the java tutorial, and on that page there are pictures of the different kind of selection modes, single selection, single interval selection, multiple interval selection. In single selection, two is selected, in single interval selection, two,three,four are selected, and in multiple interval selection, one,two,four are selected. I assume those are examples of the possible selections of JList.
However, I tried out the online ListSelectionDemo on the page there and I was unable to select more than one item after changing to the single interval selection and the multiple interval selection. Also, in the program I wrote, I can't select more than one item at a time on my JList even after changing to multiple interval selection. Am I selecting wrong or something? Is there something wrong with this computer?