Hey guys, I'm working on a tip calculator as an excercise from the book I'm using to learn Java, and I've run in to a bit of a problem. When I run this code:

import java.util.Scanner;

 public class TipCalculator {
  public static void main(String[] args) {
   Scanner input = new Scanner(System.in);
       ("Enter the subtotal of your ticket:");
   double subtotal = input.nextDouble();

       ("Enter the percentage you would like to tip:");
   double tip = input.nextDouble();

   double tipAmount = (subtotal * tip) / 100.0;
   double total = (tipAmount + subtotal);

   System.out.printf("The tip amount is $" + "%5.2f", tipAmount + "\n" +
    "The Total ticket price is $" + "%5.2f", total);


the program runs normally, until it gets to the final line ("The tip amount is $"...), at which point, the console prints out:

The tip amount is $java.util.IllegalFormatConversionException: f != java.lang.String
    at java.util.Formatter$FormatSpecifier.failConversion(Formatter.java:4045)
    at java.util.Formatter$FormatSpecifier.printFloat(Formatter.java:2761)
    at java.util.Formatter$FormatSpecifier.print(Formatter.java:2708)
    at java.util.Formatter.format(Formatter.java:2488)
    at java.io.PrintStream.format(PrintStream.java:970)
    at java.io.PrintStream.printf(PrintStream.java:871)
    at TipCalculator.main(TipCalculator.java:17)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at edu.rice.cs.drjava.model.compiler.JavacCompiler.runCommand(JavacCompiler.java:272)

I'm not sure what's causing this to happen. I'm still learning how to use the printf function, but as far as I know, I've declared it exactly as the example in the book states as the correct usage. Anybody know where I went wrong here? Thanks for any and all help.

3 Years
Discussion Span
Last Post by DeadH34d

try it like this:

System.out.printf("The tip amount is $" + "%5.2f", tipAmount);
  System.out.printf("The Total ticket price is $" + "%5.2f", total);

the printf statement follows a certain structure:
basically: String - format - value to format.
you can't just add a String at the end and expect it to work as two println statements.


Yeah, that fixed it. Thanks for the clarification, it would have taken me forever to figure that out.

This topic has been dead for over six months. Start a new discussion instead.
Have something to contribute to this discussion? Please be thoughtful, detailed and courteous, and be sure to adhere to our posting rules.