Question

public class TryMyMath {

    public static void main(String args[])
    {

        double num = Math.E;
        printTable(num);
    }// end main

    public static void printTable(double num){
        int n = 1;

        for(n = 1;n <= 10; n++)
        {
            num = Math.pow(num, n);
            System.out.printf("%d %lf", n, num);
        }
        round100th(num);

    }
    public static double round100th(double num)
    {
        return Math.round(num*100.)/100.0 ;
    } // end round100th

}

i have this question with using printf in java, so this is the error i get with printf

Exception in thread "main" java.util.UnknownFormatConversionException: Conversion = 'l'
  at java.util.Formatter$FormatSpecifier.conversion(Unknown Source)
  at java.util.Formatter$FormatSpecifier.<init>(Unknown Source)
  at java.util.Formatter.parse(Unknown Source)
  at java.util.Formatter.format(Unknown Source)
  at java.io.PrintStream.format(Unknown Source)
  at java.io.PrintStream.printf(Unknown Source)
  at TryMyMath.printTable(TryMyMath.java:15)
  at TryMyMath.main(TryMyMath.java:7)

when i take out printf statement there wasn’t any error, am I not using printf the right way it is supposed to be used in java?

and also i’m new to java and eclipse so i don’t know what those error mean.

so this is the out put that i get

1
2.7182822
7.3890563
403.4287934
26489122129.8434375
13041808783936237000000000000000000000000000000000000.0000006
Infinity7
Infinity8
Infinity9
Infinity10
Infinity

the output is only right up to n = 3 i don’t see anything wrong with the for loop why is this happen?

nvm i saw what wrong with it

Answer 1

It should be System.out.printf("%d %f", n, num). The l is meaningless here.

Additionally, your round100th(num); call has no effect – are you trying to print the numbers to two decimal places? You can do that with:

System.out.printf("%d %.2f", n, num)