How to set default value in javafx comboBox?

Question

I need to set the default value for a ComboBox from an ObservableArrayList , I am trying to set the first value in my ArrayList as the default value.

 List = FXCollections.observableArrayList(arrayList); comboBox.setItems(List); 

Answer 1

 comboBox.getSelectionModel().selectFirst(); 

Answer 2

 comboBox.getSelectionModel().select(index); 

where index is the integer position of the item to select in the selection model, or a value of the same type as the List array.