Combo boxes allow the user to choose one of several choices. There are two different kinds of combo boxes. One type features a button with a drop down list of items. The second type is often referred to as the editable combo box. This type allows the user to type in values in the provided textfield as well as allowing the user to click a button to drop down a list as well. Combo boxes take up little space making them ideal when space becomes an issue.
JComboBox myList = new JComboBox(theStrings);
myList.setSelectedIndex(4);//size
myList.addActionListener(this);//need //to add an action listener