INTRODUCTION TO OBJECTS AND INPUT/OUTPUT - Java Programming: From Problem Analysis to Program Design - page 148

str = String.format("The value of x with two decimal "
+ "places = %.2f%n", x)
+ String.format("The value of y with two decimal "
+ "places = %.2f%n", y)
+ String.format("The value of z with two decimal "
+ "places = %.2f%n", z);

JOptionPane.showMessageDialog( null , str,
"Formatting with the String Method format",
JOptionPane.INFORMATION_MESSAGE);

System.exit(0);

}

}

Sample Run: (Figure 3-13 shows the output of this program.)

FIGURE 3-13 Output dialog box showing the values of x , y , and z with two decimal places

Note that in the preceding program, first we constructed str using the String method
format and then used str in the output dialog box. However, you could have used the
String method format directly in the output dialog box. That is, you can replace the
statements:
str = String.format("The value of x with two decimal "
+ "places = %.2f%n", x)
+ String.format("The value of y with two decimal "
+ "places = %.2f%n", y)
+ String.format("The value of z with two decimal "
+ "places = %.2f%n", z);

JOptionPane.showMessageDialog( null , str,
"Formatting with the String Method format",
JOptionPane.INFORMATION_MESSAGE);

with the following statement:

JOptionPane.showMessageDialog( null ,
String.format("The value of x with two decimal "
+ "places = %.2f%n", x)