Thread: JOptionPane and StringBuilder

problem is that showMessageDialog(null, string) and not showMessageDialog(string, string)

Why can't you use the version that works with a single String? What is the reason you think you need two Strings?

If I want to show the first text "Java is cool!" using JOptionPane, then append.("I love it!) to the text, "Java is cool!" does not appear. So I assumed I needed to use (string, stringBuilder.toString() ) instead of (null, stringBuilder.toString() )

public class builderMain {
 
	public static void main(String[] args) {
		String hello = JOptionPane.showInputDialog( null, "Enter Text" , "String Builder", JOptionPane.INFORMATION_MESSAGE);
		JOptionPane.showMessageDialog(null, hello, "String Builder", JOptionPane.INFORMATION_MESSAGE);
 
		StringBuilder stringBuilder = new StringBuilder();
 
		//stringBuilder.append("");
		stringBuilder.append( " I love it!" );
		stringBuilder.capacity();
 
		JOptionPane.showMessageDialog( null, stringBuilder.toString() , "String Builder", JOptionPane.INFORMATION_MESSAGE);
 
		String yes =JOptionPane.showInputDialog(null, "Enter the string ' Yes, '");
		stringBuilder.insert(16, yes);
		JOptionPane.showMessageDialog( null, stringBuilder.toString() , "String Builder", JOptionPane.INFORMATION_MESSAGE);

Why does " Java is cool! " not remain in the stringBuilder when I compile? It says, "I love Yes, it!"

I don't see where the code is appending the String: "I love it!" to the String: "Java is cool!"?
Either use the + operator to concatenate the two Strings
or put them both into StringBuilder and use its toString() method to get the String with them both in it.