To display the first element in a JComboBox, use the getSelectedIndex():comboBox.setSelectedIndex(0);The following is an example to display the first element in a JComboBox in Java:Exampleimport java.awt.BorderLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextArea; public class SwingDemo {    public static void main(String[] args) {       JPanel panel = new JPanel(new BorderLayout());       String[] strArr = new String[] { "Laptop", "Mobile", "Desktop", "Tablet" };       JComboBox comboBox = new JComboBox(strArr);       panel.add(comboBox, BorderLayout.NORTH);       JTextArea text = new JTextArea(5, 5);       panel.add(text, ... Read More

To toggle visibility with JCheckBox, use isVisible() method:JCheckBox toggleVisibility = new JCheckBox("Hide/Show"); toggleVisibility.setSelected(comboBox.isVisible()); toggleVisibility.addItemListener(e -> {    comboBox.setVisible(e.getStateChange() == ItemEvent.SELECTED); });The following is an example to hide and display JCombobox with a JCheckBox in Java:Exampleimport java.awt.BorderLayout; import java.awt.event.ItemEvent; import javax.swing.*; public class SwingDemo {    JFrame frame;    SwingDemo(){       frame = new JFrame("ComboBox");       String Sports[]={"Select", "Tennis", "Cricket", "Football"};       JComboBox comboBox = new JComboBox(Sports);       comboBox.setBounds(50, 50, 90, 20);       frame.add(comboBox, BorderLayout.CENTER);       JCheckBox toggleVisibility = new JCheckBox("Hide/Show");       toggleVisibility.setSelected(comboBox.isVisible());       toggleVisibility.addItemListener(e ... Read More

In this article, we will learn to disable the first item on a JComboBox using Java. This setup is useful for applications where you want to show a placeholder as the first item and prevent it from being chosen, so users must select a valid option. We will be using JComboBox. JComboBox class The JComboBox class in Java is a useful component that combines a dropdown list with a button or a text field. This lets users pick an option from the list or type their input if editing is allowed. It’s great for creating forms where users can choose ... Read More

For JCheckBox, use the following to set tooltip text:checkBox1.setToolTipText("Sports Football"); checkBox2.setToolTipText("Sports Tennis");Tooltip text is visible whenever you will place cursor on that particular text.The following is an example. Here, we have set the tooltip text for both the sports:Exampleimport java.awt.*; import java.awt.event.*; import javax.swing.*; public class SwingDemo {    private JFrame mainFrame;    private JLabel headerLabel;    private JLabel statusLabel;    private JPanel controlPanel;    public SwingDemo(){       prepareGUI();    }    public static void main(String[] args){       SwingDemo swingControlDemo = new SwingDemo();       swingControlDemo.showCheckBoxDemo();    }    private void prepareGUI(){       ... Read More

To change the JLabel foreground and background color, use the following methods:JLabel label; label.setForeground(new Color(120, 90, 40)); label.setBackground(new Color(100, 20, 70));The following is an example to change JLabel background and foreground color:Exampleimport java.awt.Color; import java.awt.Font; import javax.swing.*; import javax.swing.border.Border; public class SwingDemo {    public static void main(String args[]) {       JFrame frame = new JFrame("Demo");       JLabel label;       label = new JLabel("This is demo label!", JLabel.RIGHT);       label.setVerticalAlignment(JLabel.TOP);       label.setFont(new Font("Verdana", Font.PLAIN, 15));       label.setForeground(new Color(120, 90, 40));       label.setBackground(new Color(100, 20, 70));   ... Read More

Use the setVerticalAlignment() method to align JLabel text vertically to the top:JLabel label = label.setVerticalAlignment(JLabel.TOP);The following is an example to align JLabel text vertically to the top:Exampleimport java.awt.Color; import java.awt.Font; import javax.swing.*; import javax.swing.border.Border; public class SwingDemo {    public static void main(String args[]) {       JFrame frame = new JFrame("Demo");       JLabel label;       label = new JLabel("This is demo label!");       label.setFont(new Font("Verdana", Font.PLAIN, 14));       label.setVerticalAlignment(JLabel.TOP);       Border border = BorderFactory.createLineBorder(Color.ORANGE);       label.setBorder(border);       frame.add(label);       frame.setSize(600,300);       frame.setVisible(true);    } }Output

Mnemonic key is set so that a user can use Keyboard keys to check a CheckBox. For example, a key can be set with ALT:checkBox1.setMnemonic(KeyEvent.VK_F); checkBox2.setMnemonic(KeyEvent.VK_T); checkBox3.setMnemonic(KeyEvent.VK_R); checkBox4.setMnemonic(KeyEvent.VK_C); checkBox5.setMnemonic(KeyEvent.VK_A);Above, we have set key ALT+F for checkbox 1, key ALT+T for checkBox2, etc.The following is an example. Here, we have set Mnemonic key for selection of each CheckBox:Exampleimport java.awt.*; import java.awt.event.*; import javax.swing.*; public class SwingDemo {    private JFrame mainFrame;    private JLabel headerLabel;    private JLabel statusLabel;    private JPanel controlPanel;    public SwingDemo(){       prepareGUI();    }    public static void main(String[] args){       ... Read More

Here, we have used ItemListener to handle JCheckBox events i.e. whenever any of the CheckBox is selected.For example; When any of the sports like Football CheckBox is checked, event is fired and a message is visible in the botton.The following is an example to handle JCheckBox events with an ItemListener:Exampleimport java.awt.*; import java.awt.event.*; import javax.swing.*; public class SwingDemo {    private JFrame mainFrame;    private JLabel headerLabel;    private JLabel statusLabel;    private JPanel controlPanel;    public SwingDemo(){       prepareGUI();    }    public static void main(String[] args){       SwingDemo swingControlDemo = new SwingDemo();     ... Read More

The following is an example to get or set the selection state of JCheckBox:Exampleimport java.awt.FlowLayout; import javax.swing.JCheckBox; import javax.swing.JFrame; public class SwingDemo extends JFrame {    public SwingDemo() {       setSize(500, 500);       setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);       setLayout(new FlowLayout(FlowLayout.CENTER));       JCheckBox checkBox = new JCheckBox("Demo");       checkBox.setSelected(true);       boolean sel = checkBox.isSelected();       if (sel)          System.out.println("Check box selected!");       getContentPane().add(checkBox);    }    public static void main(String[] args) {       new SwingDemo().setVisible(true);    } }OutputSince the checkbox is selected by default, the following output would be visible in EclipseIDE:

The following is an example to disable JCheckBox if not checked in Java:Exampleimport java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JCheckBox; import javax.swing.JOptionPane; public class SwingDemo {    public static void main(String[] args) {       JCheckBox checkBox = new JCheckBox("Demo", true);       checkBox.addActionListener(new ActionListener() {          public void actionPerformed(ActionEvent e) {             if (checkBox.isEnabled())                checkBox.setEnabled(false);             else                checkBox.setEnabled(true);          }       });       JOptionPane.showMessageDialog(null, checkBox);    } }OutputNow, when you will uncheck the above checkbox, it will get disabled: