Java Lesson 3: JOptionPane Dialog Boxes and Data Parsing

Key Points:

  • The JOptionPane is a class in Java that allows you to display a dialog box quickly. By doing this you can simply display info or request info from the user.
  • Inorder to use this you must import the class at the beginning of the program:
    import javax.swing.JOptionPane;
  • To do an input dialog box:
    String name = JOptionPane.showInputDialog(“Enter text” + variableName);
  • To do an output dialog box:
    JOptionPane.showMessageDialog(null, “Text” + variableName2);
  • When you use the showInputDialog the informaiton gets returned as a string, so if you want the information as a different variable type you must convert it (parse it). See table below for each data type:

    String to short Short.parseShort
    String to long Long.parseLong
    String to integer Integer.parseInt
    String to float Float.parseFloat
    String to double Double.parseDouble
    String to byte Byte.parseByte
  • Example of data parse in JOptionPane:
    String inputAge = JOptionPane.showInputDialog(“How old are you?”);
    int age = Integer.parseInt(inputAge);

View the Code Example!