The name is misleading. JComboBox does not let you select combinations of options, the way you can with a JList, just a single option. The combo-moniker comes from the fact it has a combination write in field and select from pre-existing choices.

To control how the choices are displayed, you can write a custom ListCellRenderer, based on BasicComboBoxRenderer.

To control how the new write-in field possibility is keyed, you can write a custom ComboBoxEditor based on BasicComboBoxEditor.

JComboBox uses setSelectedItem instead of select. getSelectedItem returns an Object you must cast to a String. The use of Objects for your choices allows more flexibility in rendering the choices.

Beware of the JComboBox(Vector<?>) constructor. It does not simply make a copy of the Vector. Any changes you make to the JComboBox model will also modify that Vector.

Here in how you use it:

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