Java ComboBox .selectionModelProperty ()

public final ObjectProperty < SingleSelectionModel < T >> selectionModelProperty()

//from   ww w  .  j a  v a2 s .c  o m
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Label;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;

public class Main extends Application {
  public static void main(String[] args) {
    launch(args);
  }
  @Override
  public void start(Stage stage) {
    Scene scene = new Scene(new Group(), 450, 250);
    ObservableList<String> list = FXCollections.observableArrayList("1","2","3","4");
    ComboBox<String> emailComboBox = new ComboBox<String>(list);
    
    emailComboBox.setValue("A");
    System.out.println(emailComboBox.selectionModelProperty());
    
    GridPane grid = new GridPane();
    grid.setVgap(4);
    grid.setHgap(10);
    grid.setPadding(new Insets(5, 5, 5, 5));
    grid.add(new Label("To: "), 0, 0);
    grid.add(emailComboBox, 1, 0);
    
    
    Group root = (Group) scene.getRoot();
    root.getChildren().add(grid);
    stage.setScene(scene);
    stage.show();

  }
}