Question

I got a combobox, and a submit button, when the button is submitted, i want to check if the combobox value was null. Im using this code:

ComboBox.setSelectedItem(null);
 if (ComboBox.getSelectedItem().equals(null)) {
           infoLabel.setText("Combo box value was null");
} 

i am getting this error when i press the submit button:
java.lang.NullPointerException

how can i fix this?

Answer 1

You can not call equals on null. Instead simply use == null.
Something like this:

ComboBox.setSelectedItem(null);
if (ComboBox.getSelectedItem() == null) {
    infoLabel.setText("Combo box value was null");
} 

Should work.