CODEWITHSUNDEEP
java
user2734475
user2734475

Reputation: 61

What am I doing wrong? Java IllegalFormatConversionException

I have some code for calculating properties of a circle:

package circleinfo;

import java.util.Scanner;

public class Circleinfo {

    public static void main(String[] args) {

        Scanner input=new Scanner(System.in);
        int r;

        System.out.print("Enter the radius of the circle to find circumference, diameter, and area\n");

        r = input.nextInt();

        System.out.printf("The circumference is %f\n",(2*r*Math.PI));
        System.out.printf("The diameter is %f\n",(r*2));
        System.out.printf("The area is %f\n",(r*r*Math.PI));

    }
}

It calculates circumference, but not the rest. 

Enter the radius of the circle to find circumference, diameter, and area

10

The circumference is 62.831853

Exception in thread "main" java.util.IllegalFormatConversionException: f != java.lang.Integer
    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 circleinfo.Circleinfo.main(Circleinfo.java:30)
The diameter is Java Result: 1

Upvotes: 5

Views: 35502

Answers (3)

Victor Fernández
Victor Fernández

Reputation: 9

This is because you had to put %d format instead of %f in the result of the diameter

import java.util.Scanner;
public class CircleInfo{
    public static void main(String[] args){

            Scanner input = new Scanner(System.in);
            int radio;
            System.out.print("Input radio: ");
            radio = input.nextInt();

            System.out.printf("%s%d%n","Diameter= ",(2*radio));
            System.out.printf("%s%f%n","Area= ",(Math.PI*radio*radio));
            System.out.printf("%s%f%n","Circumference = ",(2*Math.PI*radio));
    }
}

Upvotes: 1

Narendra Pathai
Narendra Pathai

Reputation: 41945

(r*2) will be an int and not a float as r is int and 2 is int. Use %d instead

%c          char    Character
%d          int         Signed decimal integer.  
%e, %E      float       Real number, scientific notation (lowercase or uppercase exponent marker)
%f         float    Real number, standard notation.

Upvotes: 3

arshajii
arshajii

Reputation: 129507

r is an int, so r*2 is also an int, meaning that in your second print statement %f cannot be used. Try %d there instead.

Recall that %f is for floating point numbers while %d is for integers. This is outlined in the documentation of Formatter (see Format String Syntax).

Upvotes: 9

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