CODEWITHSUNDEEP
java
calvin2011
calvin2011

Reputation: 377

Having difficulty formatting output to 3 decimal places

I'm very new to Java and I'm just trying to get through some class exercises.

I've been given the task of calculating a user's perimeter and area of their circle from a given radius.

import java.util.Scanner;

public class Circle {

    public static void main(String[] args) {
    System.out.println("Please enter the radius of your circle below: ");

    Scanner input = new Scanner(System.in);
    float r =input.nextFloat();

    float p = (float) (2 * Math.PI * r);
    float a = (float) ((Math.PI) * Math.pow(r,2));

    System.out.format("Your perimeter is %.3f", p + " and your area is %.3f", a);

    }
}

This is my code so far, and I'm pretty sure it's all I need, but the compiler is throwing the error:

'Exception in thread "main" java.util.IllegalFormatConversionException: f != java.lang.String'

I've tried playing around with the System.out line a few times but I can't figure out where I'm going wrong!

Any ideas? Thanks in advance :)

Upvotes: 0

Views: 69

Answers (2)

Reimeus
Reimeus

Reputation: 159784

p + " and your area is %.3f" is being interpreted as a String due to type promotion. Use

System.out.format("Your perimeter is %.3f and your area is %.3f", p, a);

Upvotes: 5

turingcomplete
turingcomplete

Reputation: 2188

    System.out.format("Your perimeter is %.3f and your area is %.3f", p, a);

The reason is because the format method expects the first arg to be the format string followed by a varargs of objects to printed. You were passing a string as the second argument and you were trying to format it as a float, which caused the exception to be thrown.

Upvotes: 3

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