JAVA OptionPane.showMessageDialog output formatting for decimal

Question

I am very new to Java and playing with displaying a message with GUI. So if use the console

System.out.printf("Your total montly bill is $%.2f",  totalCost); 

gives me the output with decimal the way it should. I am trying to do the same thing with this, but I get more digits after the decimal because totalCost is a type double. How can I format the output to only show two digits after the decimal? Thanks.

JOptionPane.showMessageDialog(null, "Your monthly payment is " + totalCost);

Answer 1

You could do:

JOptionPane.showMessageDialog(null, String.format("Your monthly payment is $%.2f",  totalCost));

Answer 2

double d = 1.234567;
DecimalFormat df = new DecimalFormat("#.##");
JOptionPane.showMessageDialog(null, "Your monthly payment is " + df.format(d));
System.out.println(df.format(d));

Class DecimalFormat API

Answer 3

You can also do: JOptionPane.showMessageDialog(this, "Your monthly payment is " + totalCost);

Answer 4

DecimalFormat df = new DecimalFormat("#.##");
                String hour = JOptionPane.showInputDialog("Please input your hourly salary: ");
                double hr = Double.parseDouble(hour);
                double dr = hr * 8;             
                double wr = hr * 40;
                double mr = hr * 160;
                double yr = mr * 12;

    JOptionPane.showMessageDialog(null, "Yearly: " + df.format(yr) + " / " + "Monthly: "
                    + df.format(mr) + " / " + "Weekly: "+ df.format(wr) + " / " + "Hour: " + df.format(hr),
                    "Yearly Salary Calculator by the hour", JOptionPane.OK_OPTION, icon);