Question

I want to display all elements in an ArrayList, except element 10 (which is the word “will”). How do I do this? When I run the below code it shows nothing.

 private void practiceButtonActionPerformed(java.awt.event.ActionEvent evt) {
     ArrayList <String> practice1 = new ArrayList();
     Collections.addAll(practice1, "If", "she", "boarded", "the", "flight"
                        , "yesterday", "at",  "10:00,", "she", "will", "be"
                        , "here", "anytime", "now.");
     contentTextPane.setText(practice1.get(0+1+2+3+4+5+6+7+8+9+11+12+13));
 }

Answer 1

The line

practice1.get(0+1+2+3+4+5+6+7+8+9+11+12+13)

Does not do what you think it does. This will compute the value of 0 + 1 + 2 + … + 13, then look up that entry in the ArrayList. Since your ArrayList doesn’t have this many elements, it will throw an IndexOutOfRange exception.

If you want to display everything except the tenth element, try using a loop:

StringBuilder builder = new StringBuilder();
for (int i = 0; i < practice1.size(); i++) {
    if (i != 10) {
        builder += practice1.get(i);
    }
}
contextTextPane.setText(builder.toString());

Hope this helps!